outland144k
Sanderxpander
M Audio Fast Track Pro.
I've got a couple of these at school and will probably need to replace them pretty soon. With each update to Win7, they become a bit more unstable. They are also legacy at this point. Avid's site for the drivers states that they will not be compatible with Win10.
Ha, that was my first interface and I put that little box through some real hell. When I upgraded, also to a MOTU box, I gave it to a friend and he's still using that thing. It wasn't top of the line but it did the job and did it well.
outland144k
OTOH, I've also got a MOTU Midi Express 128 midi interface. Cakewalk often will not recognize it when starting. After I re-plug in the USB cable, it's stable, but I have to adjust the midi connections in SPlat for the blip. I can't speak for the audio interfaces, but I've always had the impression (especially after talking to their "support staff") that Windows is generally a low priority for MOTU. Maybe that's changed, but I wish their driver for the Midi Express 128 was solid.
I have a MOTU 8pre, the firewire version, running on my home-brew computer on Windows 10 x64. The original MOTU was about 10 years old and worked pretty damned well for me until just recently when I got a little ham-fisted and broke the multi-function knob on the front panel. Fortunately MOTU has an awesome program where you send them the out-of-warranty old unit and $99 and they'll ship you a factory-refurbished unit of the same model/series. I took advantage of that late last year and I expect I'll get another ten years out of it. In fact, I expect firewire to become unavailable before the box gives it up.
After a major OS update odd things tend to start happening and I have to uninstall and reinstall the drivers to restore it to normal operation. I've also never been able to do real-time monitoring with this interface, but I don't really need to so I can't say I've tried very hard to get it working well. (I use guitar rig in standalone mode for monitoring while recording bass and guitar and nothing at all for vocals, but the interface has lots of routing options built in that could do the job if I ever needed to do that.) It has settings for as low as 64 samples but I usually run it at 512 to get stutter-free playback, and sometimes higher when mixing/mastering. It has worked very well with both Sonar and Reaper.
I hasten to add that I've never really tried hard to optimize my computer or the OS for low latency operation. My computer, while powerful isn't specifically designed for real-time audio, but I've never really found that to be a problem for me. I do agree that MOTU places less emphasis on Windows in general, but this interfaces has been a real workhorse for me despite it's quirks. It's been a very solid device for my home studio. If I had to depend on an interface for my living I'd personally opt for an RME device but the 8pre is most certainly capable of handling that workload, particularly when coupled with a Mac.