New Interface: Zoom UAC-8 vs Focusrite Saffire Pro 40?

I'm currently in the process of upgrading my studio, from my DAW desk furniture to my computer's OS (bought a larger SSD drive and will install Windows 10) to an eventual upgrade to SONAR Platinum, but the heart of the upgrade is a new audio interface.
 
For the past 15 years or so, I've been using an ESI Waveterminal 192M PCI interface, which has served me well, but the no-longer-updated drivers seem to freeze my Sonar X3e every so often on Windows 7, and I also realized it's time to grow up and get a non-PCI interface.
 
What started out as intending to buy a Presonus Studio 192 led me on a search for other interfaces. My requirement was to find a new interface that was rackmountable, had low-latency drivers, was reliable and also had the flexibility to have ADAT/SPDIF/Word Clock/etc. I wanted either USB-3 or Firewire (I still have a compatible Firewire card). For some reason, I'm not fully sold on USB2, mainly because I'm afraid all my other USB peripherals will get in the way of A USB-2 interface's performance, plus most of my PC's USB jacks are USB-3, and USB-2 interfaces reportedly only work well when plugged into a USB-2 specific jack.
 
I've settled on two contenders, the Zoom UAC-8 and the Focusrite Saffire Pro 40. Here's my rationale:
 
Zoom UAC-8
https://www.zoom-na.com/products/production-recording/audio-interfaces/zoom-uac-8-usb-30-audio-converter

PROS:
-USB-3 interface
-24 bit/192khz
-Reportedly very low latency drivers
-New model
- So far positive reviews
 
CONS:
-Wall wart power
-Zoom lacks experience in audio interface market
-Not familiar with Zoom interface preamp quality
-Very little solid performance reviews on this product
-Drivers might still need more updates to solve issues
 
Focusrite Saffire Pro 40
https://us.focusrite.com/firewire-audio-interfaces/saffire-pro-40/artists-reviews#media-reviews

PROS:
-Firewire speed and longtime reliability
-Focusrite preamps has great reputation in audio interface market
-Reportedly very low latency drivers
-Stable, developed drivers
 
CONS:
-Older product
-Firewire is dying out
-Only 24bit/96khz
 
Can any experienced users of either chime in and help my make my decision? 

AT
I'd pick the zoom of the two.  Otherwise, I'm pretty happy w/ a TASCAM US 20x20.  Sounds great, has all the pro features (WC, ADAT, Spdif), a good ole fashioned soft mixer board layout, the back layout printed on the top of the unit (nice for home studios w/o racks), plus, it sounds great (not as nice as the UH-7000 but close enough for 8x8 work).  I was really surprised by how much you get for $400 or so.
 
Drivers have some latency, but they continue to work on them (they should be ripe for a newer version - all their new US line shares drivers and they have driver-writers in house).  If latency is your most needed feature, you'll probably want to skip it (or wait for newer drivers), but otherwise, it is a really good deal.

Just to clarify, your post was generally talking about the Tascam unit, correct?

Never been a big fan of Zoom for some reason. There stuff always seemed like toys to me. Focusrite has a stronger history in the audio world, and I've been happy with their products that I own. Personally, I would go with the Focusrite. That said, I've never owned any Zoom products, and my opinion of them have been based on appearance and my limited use of a couple products. The Zoom interface might be great, for all I know.

I finally bought an interface; it was a Focusrite Scarlett 18i20 2nd Generation. It's USB 2.0, but so far so good. The latency is really good for my softsynth needs.