I know that firmware updates for the AVB higher units are done via Ethernet, and PC connectivity via USB for audio, and thunderbolt for ultra-low latency audio connectivity (already for mac, but I think he's saying the drivers for thunderbolt are still being developed for PC).
 
I use a MOTU older audio interface (UltraLite-MK3) and never had any horror stories. The drivers are pleasantly stable and provide good low latency performance even under heavy loaded projects. Got my unit around 2007 or 2008, and it's still running satisfactorily. 

rodreb
I'm confused. Why do you need USB AND Ethernet? Why not just USB and done?

If you connect the Ethernet port to a WiFi router, you can use a tablet to remotely control the AVB units.
Works exactly like the newer generation digital mixers...
Because the control applet is browser based, you're not locked into a particular tablet or smart-phone.

Yes Rob, I just bought the Motu 24AO. I came on here because I have a problem using it with Sonar Plat. When I first got the unit I removed one of my Delta 1010LT cards. I used to get small ticks and pops now and then, because with Win 7 Drivers, they claimed you may have a problem using two cards for 16 channels. I plugged the Motu 24AO, into a USB 3 slot on my computer, it loaded the drivers from the web with no problem, and took about 7- 10 minutes, All the screens came up and it looked great until I started Sonar. The Delta Audio driver popped up but nothing of the 24AO. I re-checked and it said there was no USB connection to a AO unit. I swapped the USB3 with another USB3 socket, and nothing happened until I used a USB2 socket. It sounds great. The other setback was I had to disable the Delta card, you cannot use both when you assign your audio cards in Sonar. The 24AO is for outputs only, and optical inputs (trying next?), I wanted to used the Delta 1010lt card for inputs, and the 24AO for the outputs. I even enabled the onboard motherboard audio card, for audio input, and it doesn't even show up in the Sonar settings with the 24AO connected. Now I have to buy a analog input unit with optical output, or the 24AI (I don't need that many input$) or another Motu unit that works with the 24AO with less inputs and money. Before using the 24AO with Sonar, I could assign any audio device connected to my computer to the outputs or inputs, but synching was a major problem, if used together. When the 24AO is connected with the Delta card, if you check the box of one, the other unit becomes greyed out. I was hoping someone on here knew how to get the audio cards to work with the 24AO together? 

Solved:
After coming back on the website, I searched until I found my answer. Only 1 ASIO device can be used at one time on Sonar. So I have to choose between the Delta 1010LT (to record) or the 24AO. I cant record audio with the 24AO, until I buy a A/D ADAT converter. I think I'm going to try the Behringer 8200, they say it sounds better than the 8000. Buy a ADAT optical cable, and a BNC cable to clock the 8200 from the 24AO.

The Motu 24AO so far is great, coming from 8, then 16 to 24 channels. I tried a few of my songs, and assigned the instruments to as many different output tracks as possible, and I had no problems until I had one song with a loud guitar and a sitar, it dropped out a few bars. I adjusted the communications rate to the lowest latency rate, and it's never drops a note now. Think I'll order the Behringer ADAT 8200 this weekend and add some vocals, and see how that sounds, I'm not spending almost another $1000, for the 24AI. 24 channels seems to be enough output channels for me to mix down from. It also takes up half my mixing board. Happy camper so far. I was ready to jump on the 24AO in January, but there was conflicting specs on where you checked to buy about it's use with Win 7, only Win 8 and above, and no Windows support. After going to Motu website in Mid August, they stated that it was compatible with Win 7 and new drivers were there, so I bought it. The way I record, I never used more than 8 audio inputs at a time, so the 24Ai would be a waste.  

richlion821
After coming back on the website, I searched until I found my answer. Only 1 ASIO device can be used at one time on Sonar. So I have to choose between the Delta 1010LT (to record) or the 24AO. 

The ASIO spec itself imposes the limit of one ASIO "device".
IOW, You'd have the same scenario with any DAW software.
 
Manufactures can get around this limitation by having two (or more) of the same (or same series) audio interfaces sharing a single ASIO driver.