I have both and both have pros and cons. Acrylic is lighter, so easier to transport and less weight on the floors. Acrylic is stronger, so less chance of cracks or leaks after it's filled with water. Acrylic looks nicer with its rounded corners and no aquarium sealant lines. Acrylic scratches very easily and can only be cleaned with special pads made for acrylic (or you'll scratch it up real bad), luckily the scratches aren't very noticable when the tank is filled with water (unless the scratch is real bad). Glass doesn't scratch easily, so scraping algae is easier. Glass will stay in perfect condition longer than glass due to the scratching problem, but personally I haven't had an acrylic tank that became unusable, so length of life I don't know about, as far as I know they would be equal. (although if you drop an acrylic tank, it will have a better chance of survival than a glass one, hahaha). I would just shop around and find your best deal, whether it be glass or acrylic, I think both are fine.
Linda