========== UPDATE ========
Here's another update - after tracking guitar all day at the second lowest latency setting (128 samples - 7.8ms RTL) this audio interface sounds terrific, and performed flawlessly.
I even rigged up the mixer to strap a (LA2A) limiter over the guitar input (well, I'm using the XLR mic input to record guitar).
 
The web interface goes a little wacky when you access the mixer - but I figured out that it just needs to be minimised, and then open it again and it's fine ;-)
 
Anyway - I think (unless something stupid happens in the next few days) I'll be keeping this - and will highly recommend it.
 
Thanks again to Jim R - for starting the topic...
 
EDIT - I just have to get used to turning the thing on every day - it doesn't seem to have a way of coming up automatically when I power on my "studio" ;-)
Also - I moved it to a mobo (Asus P8Z77-V) USB3 port and it seems fine.

Starting with the Z77 chipset motherboards, USB3 was integrated into the Intel chipset.
This eliminates many compatibility issues.
Think of it being similar to using TI chipset Firewire...  
 
Glad to hear the Ultralite AVB is working well for you!
The Web based control-panel is a little sluggish (I'm impatient), but it's also extremely flexible in that you can control it via any smart-phone, tablet, or computer (regardless of platform).

Jim Roseberry
Starting with the Z77 chipset motherboards, USB3 was integrated into the Intel chipset.
This eliminates many compatibility issues.
Think of it being similar to using TI chipset Firewire...  
 
Glad to hear the Ultralite AVB is working well for you!

that explains why the first one wasn't so good. I went out and bought a PCIe card with a couple of USB3 ports on it - so the ultralite wouldn't be "sharing" with anything. Not to worry - it seems really happy on the integrated USB3 port.
 
 

The Web based control-panel is a little sluggish (I'm impatient), but it's also extremely flexible in that you can control it via any smart-phone, tablet, or computer (regardless of platform).

I was a little worried when I had "connection" problems - but it seems pretty good now. Also, like i said, the mixer problem goes away when you minimise and then go back in to it.
 
I should also say that I'm running at 24 bit/44.1 Sample Rate.
I may never get my PC to run at 4.9ms RTL - but I couldn't do that with the PCI interface either. I feel better spending a little more (althought they've come down in the last few months) for an interface where at least there is a *possibility* to go that low - so it's not running at it's lowest setting, and still giving me very workable latencies.
MOTU seems pretty good with driver support (like RME) so hopefully I'll be running with this for a long time now... ;-)
 

I just purchased this unit as well and it's been flawless for me under Windows 10. I'm on an x58 Gigabyte x58a-UDR3 board with an i7 950. It seems to work fine on either the built in USB3, USB2 or an Ankor USB3 PCIE card. 
I can run 44.1k 64 samples with an RTL at 4.9msec in Reaper or Studio One and 5.1msec measured with Oblique software. I'm running some heavy VSTi like Ivory with 1000 voices and all the bells and whistles turned on and I don't get any crackles or pops.
I too replaced a Delta 66 card and the difference in sound quality is noticeable. 
 
About the only time I have any skips or dropouts is when just listening to mp3 and surfing the net during down time. Once in a while it will skip. It does it with both the onboard NIC and an add in NIC. The Delta 66 card would do this on occasion as well so I suspect it's something to do with the IRQ layout on the board.
 
One odd thing I can't explain is that with my Delta 66,( 4.4msec at 64 samples/44.1k) I could not tolerate 128 samples playing Ivory but with the MOTU I can even though the RTL is slightly higher. Doesn't make sense but it's true.
 
It's a keeper in my book and seeing as the chatter on the net regarding the Presonus Studio 192 (my second choice) RTL being not so good I'm happy with my purchase.
 
P.S. I wish there was a way to turn off the LCD. I wrote MOTU about it. Seeing as the web application can blink it there should be a easy way to add it to the code in the web application.
 
 

flawless for me under Windows 10.

steveo - I'm glad to hear that, as that will be my next big "upheaval" ;-)
 
Are you doing anything special to get the 4.9ms RTL? I'm assuming that my CPU/mobo (i7 3770K/Asus P8Z77-V) just can't cut it.

What I did was a clean install of Windows 10 professional on an SSD drive. Also have Ivory on a separate SSD drive and my other samples, audio are both on 2 WD Black 1TB drives.
I laid out my USB strategy so that the MOTU is on it's own USB2 onboard port and all my other devices are on an add in USB 3 card. 
About the only sketchy part of my outdated system is the Nvidia GT630 card. It seems to generate high  ISR level according to latest LatencyMon program
"Driver with highest ISR routine execution time:       dxgkrnl.sys - DirectX Graphics Kernel, Microsoft Corporation" 
This board shares slot irq and there seems to be no way around it. I have also turned off C-states etc and parking as well.
Other than that, here is my modest system:
 
Intel Gigabyte x58 UDR3 i7 950
16G memory
Samsung / PNY SSD for OS and Ivory, qty 4 WD Black 7200 RPM drives.
Windows 10
Nvidia GT 630
MOTU Ultra Lite AVB
Event ASP8 Monitors
 
 P.S I'm a long time Cake user going back to the Pete Leoni / Catena days. 

 P.S I'm a long time Cake user going back to the Pete Leoni / Catena days.

So am I! We've probably "met" before
 
Oh well, I'm not really in the mood for a clean install (not ready for Win 10 yet anyway). I'll play around and see if I can get the latency down - it's not imperative, as it's working fine at 7.8ms RTL...

Nice to meet you! Again!  lol
From my understanding, the latency number(s) is set by your hardware as well as the driver and how efficient it is.
Unlike DPC spikes, I don't believe there is much you can do to mitigate it.
 
So if you select "Minimum Latency" for Streaming Mode and 64 Samples for ASIO Buffer Size, both in the AVB Control Panel, you can't reach approximately 4.9 ms RTL reported by Sonar or another DAW?
 
Or, if you can reach that number, is it unusable, meaning pops and clicks etc?
 

steveo42
Or, if you can reach that number, is it unusable, meaning pops and clicks etc?

This ;-)
 
SONAR reports 4.9ms latency but it's not usable unless I have maybe 1 or 2 tracks of audio maximum.
On a "normal" project (fairly modest at maybe 8-10 audio tracks with amp sims and console emulators) plus a few soft synths - it's either crackle city, or else I get a little "burst" when the project loads - then no sound. It plays fine, but no sound - even when I reset the audio engine.
 
On a test project - it seems fine when I disable all FX (with the button in the control area), but I don't know if that's because of the FX or the CPU use going down. Mind you - the CPU is not very high (unless th emeters are inaccurate) so I think it has something to do with the plugins. Perhaps certain plugins are less happy running with 64 sample buffers?
 
 
I've had more fun and games too. SONAR works great (at 7.8ms RTL) and Windows sounds have been fine too (ie Windows Media Player) - but CD Architect was very unhappy yesterday. When I changed from a ASMedia USB3 port to a Intel one (they're all built in to the motherboard) - the CD Architect is fine (so is everything else).
I had favoured the ASMedia port because it 9well, there are two)  doesn't share an interrupt with anything else on the mobo - where the Intel USB3 ports share with the USB2 ports and some (empty) PCIe slots.
 
I'm not used to USB interfaces - so this is just fun and games. Once I get it settled down so that everything works and is happy - then I can occassionally play around to see if I can convince SONAR to run at 64 samples...

I did some more testing at the lowest latency (4.9ms RTL). If I start a new project:
- load Trilian, Superior Drums and Kontakt (empty) - it's fine.
- add 10 stereo audio tracks - it's fine.
- Add a couple of amp simes - OK
- add a couple more amp sims - it starts crackling a little and "beeping" once in a while
 
So these tracks could be bounced, and it would be OK (I tried another test project with a lot of bounced audio tracks (so no amp sims) and it's OK too).
 
So I'd say it's just a case of my PC being *borderline* able to support this lowest latency. The CPU usage is not atrocious (like I thought it would be) - so the drivers are *good*.
I think this interface will definitely be a keeper - and my (comfortable working) latency is *marginally* higher (1 or 2 ms RTL max) than with the PCI card Delta66.
 
On the plus side - it sounds great, it's actually supported and we know it's also supported on Win 10 - and hopefully it will remain supported for a long time to come ;-)