I was about to post the same thing!
I have a blowdryer I've had for many, many years, and a big bold diffuser that I got from some unethical means (I stole it from the gym locker room in my early 20's. Please don't send me to jail). I use it just so I don't have to spend the day with we hair--a little more frizz than air drying, but worth it to cut down on drying time.
I was at an Ulta and I asked, and the woman was completely and utterly useless. The only thing she could tell me was that she recommended Hot Tools brand, and that if you spend more money you can get one that's lighter. I explained I don't care how heavy it is, because I just sit there with my hair in the diffuser for like 5 minutes. But she couldn't tell me anything about the other options!
Ionic? Ceramic? What kind of diffuser--bowl, the kind that's like flat with the little pegs sticking out, or the crazy Deva hand-shaped thing?
I will spend more money if it actually dries my hair faster and less frizzy!
"I don't know! I don't know why I did it, I don't know why I enjoyed it, and I don't know why I'll do it again!" -BART SIMPSON