I voted acrylic. I like the clarity and the fact that it is so light weight. My main reason though is this......my tank is 500 gallons....now for the sake of this argument we are going to imagine what 500 gallons of water, 560 lbs of LR and 840 lbs of substrate would look like as a glass tank exlpoded and went rushing through the back wall of my house taking the french doors and the furniture with it!
I would not buy a glass tank over 180 gallons or so although I know there are plenty of folks that have them.But I think most would agree that an acrylic tank is less likely to fail (contrary to what someone else has posted here). I can deal with a scratch here or there, but I can't handle a broken glass tank spilling that much water into my house.
Just a thought!
Elizabeth