I wish the SL viewer was more stable in OS Sierra 10.2, Ive been on SL for almost 10 years and all this time ive gone through 5 different Mac computers.
It wasn't until recently, that I upgraded to my latest, a late 2015 iMac and Ive noticed constitently crashes, so frequently that I can barely do anything at times, crowded places are almost a no go and if I do make it, I have to be on pretty low settings, I will still crash eventually. Even when Im at home with just me and maybe 1 or 2 more avatars I can't even turn on the high settings without crashing down the road too.
Its really a shame this hasn't been fixed somehow yet, its frustrating having to be crashing so frequently when other people rarely do.