I use windows 7, and I also have installed SST ver 6.6.6.9 (the newest one on their website).
It works just fine.
And yes I do use SST for Aces High.. The majority of the buttons are programmed in through AH, but I have quite a few also programmed through SST... for example when I depress SHIFT+"C", it sends the "/" key to AH to open the text buffer (useful to see who is in range or on channel). When I RELEASE SHIFT+"C", it sends "ENTER" to AH to close it.
SHIFT+T1 sends "/.salvo 1 <ENTER>... I use my throttle slider for my views... LEFT 33% sends F1 (cockpit view), MIDDLE 33% sends F3 (external view), RIGHT 33% sends F5 (god's eye).
This kind of stuff you can't program in through Aces High.
I also have bunches more programmed in.. literally the only thing I have to use the keyboard for is to type text messages.