I've been keeping reef tanks since about 1988. Up until last Fall, I'd never had an acrylic tank. All glass, all the time - from 10 gallons all the way up to 265. OK, I did have a plywood tank once ...... once! Last Fall I went acrylic for my current 450/400. So far, I've no reason to regret it, and plenty to be happy with. Of course acrylic scratches more easily, so you have to be smart about it. Don't let calcified algae build up, and buy a good quality magnet cleaner. If you cannot do either of these, get glass. Albano hinted at it earlier, but do your lighting to minimize the amount that falls on the front panels. I actually use blanking panels to shade the front of my tank. I'm not growing corals there after all. So cleaning is really a snap. 5 minutes a week with the MM. I also designed the stand with a raised front edge that prevents me from accidentally dipping the magnet cleaner into the sand. Every couple of months I remove it and get in there with the dozer pad.
The one thing I like particularly with acrylic that has not been mentioned is the the clean, clear corners. On a well made tank, they are pristine. A thick line of silicone was always an eyesore to me, and it's almost impossible to keep it coraline free or un-tattered.
I certainly cannot speak to the longevi of my tank, only having had it for 9 months. I had a 180 last me for almost 18 years, so that's a tough standard to meet. But, we shall see.
