In years past the layouts have been lacking in a lot of aluminum rigs. The weekend angler would be fine with them, but if you look at most guys who fish tournaments, they have more gear than your average guy. Most aluminum's are marketed to the entry level crowd, so a lot of them are in that 16-17' range and lack space and storage. They aren't made to handle as big of water as the 19-21 foot boats. My friend has a Tracker 175 txw with the "smooth ride hull" it was anything but smooth when it got choppy. My old 16' Ranger ran smoother in rougher water than that did. Another plus for the glass boats is that they're normally rated for higher HP and are able to run faster. Another example including the Tracker 175 of my friends is that his has a 50 on it and will run 31 to about 33. It's rated for a 75 and even with that it'd max out at about 40. My 17 foot Ranger is rated for a 130 and will run into the low 50's.
As far as durability is concerned, with fiberglass you need to watch out for rocks and metal. Wood generally doesn't bother either. Paint or decals on aluminum can be scratched just as easily.
In recent years the aluminum boats have become better boats than before. Brands like Xpress, and Lund have been out to get a market share in the higher end bass market. They've adopted the size and layouts of the glass boats and are very competitive in the market In the mean time the entry level boats have gotten better as well. There are a few guys who fish out of tin's in the bass club I'm in and they do just fine. Definitely nothing wrong with them and they should be seriously considered, but in a lot of cases glass will offer you a few more options and amenities.