Just got one of these. Any one else here running Platinum on one?  My win10 machine likes it but still no luck with win7 sp1 drivers. Just trying to find some friends with this interface and sonar.

The 20x20 looks like it would be a very good interface.  Sorry I can't help with drivers.

To run the US-20x20 USB3 driver, you need Win10.
 
USB 3.0 is used in the US-20x20 for (24) channels transmission at 192kHz/24-bit. This is not possible with USB 2.0.
USB3.0/USB2.0 Windows 10
USB2.0 Windows 8, Windows 7, OS X Yosemite(10.10), OS X Mavericks(10.9), OS X Mountain Lion(10.8)

I read all that and was using the usb 2.0 cable and did not see any other drivers to choose from. The driver shows up in the device manager with an explanation point saying that it's not digitally signed however, when i click on update driver from web it says I already have the best one.

There is a warning about all that in the manual.  The drivers went down fine on my win7 machine and everything (so far!) is working as should. 

Hey J.A.--
Do you use the midi in on back of your 20X20?
If so any problems?
 
I have a Yamaha DTX500 drum module that kicks the 20X20 drivers out no matter what I try.
Going back and forth with Tascam they blame Yamaha who blames Tascam.
Just wondering if you have success with your midi in