I'm so accident prone I can scratch glass (I frag a lot and move rocks a lot) for a hands off display I would consider acrylic, but a working display/propagation tank I'm sticking with glass If I were to go 120 or larger I would go acrylic because of the reliability mentioned above. I dont like the smaller access holes of acrylic tanks they make it too restrictive for my working preferences, I say depends on the application. If your going display only or extremly large go for acrylic, If your gonna frag and stay small (realitively) I would vote glass. But thats just my opinion. either has pros and cons.