I have three SM notherboards on-line now. I love 'em. They're the most stable PC I've ever run (and my first PC was an IBM AT a decade or so ago....).
I've tried Asus, Tyan, Amptron (got a deal onnit)...SM is my favorite.
The two most current systems are on a SM P4DCE+ (Dual Pres. Xeon 2G) and a 370DDE (Dual PIII 1G). THe other SM baord is pretty old, but still cranking...never had a problem with it (couple years).
SM is not a good OC board (Intel Chipsets), but they're hard to beat for stability. I use mine for video rendering and editing (Premier 6).
FWIW
Scott