I believe that the hype about short ata is way overrated. Yes it is easier to cant the bow . I have owned a firestorm lite for about a month now and have had no problems with cant. If you are shooting more weight than you can handle I can see where a problem may arise but if you are shooting a comfortable weight I don't see the cause of said hype.
The problem of canting your bow will not be very evident at normal hunting ranges. Where you will see a big difference is on the target range, especially on shots of 40 yards and beyond. When you're trying to hit a small target at great range, it is very obvious. Do you have a level on your bow? Just wondering. I was once shooting a 48" ata bow and decided to take some shots sitting on the ground. In order to shoot the bow, I had to cant it a lot. And in order to hit the bullseye at 20 yards, I had to aim the canted bow 6 inches to the right (I'm right handed, and shoot w/ fingers). Once I learned that, I could repeat it at will. This is a very extreme example, but it does show the effect of canting. Also, the smaller the target, the more evident it is to see the results of canting. Hence levels on bows shot in indoor tournaments (20 yards) where the X ring is 1 7/8" in diameter.