Acrylic is a bit more forgiving if you accidentally bump the tank, as it will flex before it will break. As you pointed out, yes, it scratches rather easily, and care is needed to clean it properly. Assuming that the tank will be freshwater (since it was under the freshwater section) you won't have to worry about what MH lights do to the seams of acrylic tanks. The only other down side I can see is the fact that the acrylic may change colors and become slightly opaque over the years... but they're supposed to be good for at least 10-15 years. Some people prefer acrylic, some prefer glass. Ultimately, it will come down to which one is more visually pleasing to you.
Money is also a key factor in deciding which way to go. Acrylic tanks are for the most part a bit pricier than their glass counterparts. On the other hand you tend to get a better warranty than most glass tank mfgrs. are willing to offer. You will need a stand that completely supports the entire bottom of your acrylic tank. I like mine (price !$$$$!). It's been over 2yrs. & the couple of minor scratches that popped up polished right out. "T"
