AT's often get a bad rap so I wanna mention what AT's have done for me.
By using AT's when first learning the game I was able to easily pick out a toon with a powerset that resembles one of my favorite CoH toons, give him a name, and a look.
With all the time I saved from not having to learn the FF system and guess what I think would work best in a game I never played... I learned things like which currencies are important to new players (Q - Zen - G), how to use the Q Exchange, Auction Exchange, how to line up my cones, how mob ai works, how hard mobs hit and how hard I hit them, which travel powers I like best, how I can interact with the geography, how to play with the character creator/hud/game setup options and etc. And, I still made toons that were a credit to the teams they join.
By using AT's I've become familiar with SS's and Talents and Specializations and Powers and Devices and have gathered enough info to get an idea of which ones fit my playstyle.
If you choose an AT you play well and get it to 40 and gear it, if nothing else, he will be a farming toon for you that can net you, daily, at the very very least an easy 2k of Q anytime you want to run 3 (you should rarely fail) alerts.
I'm of course looking to forward experimenting with FF's but I have fun playing my AT's and they have been really useful to me.