I got really sick of taking half an hour to dry my hair with my old dryer but my hair doesn't air dry very quickly so that wasn't an option.
I did a lot of research on faster hair dryers and decided this one was worth the investment - NO REGRETS!!! I actually have two as I used to leave one at my boyfriend's place but we live together now so I take it with me if I stay at my friends' place.
My hair (long) dries in less than 10 mins from towel dry. I like to start with the hottest setting and as my hair gets dryer, I reduce the heat. I end with the cool shot as this really helps with my frizzy hair. It also really helps to curl my hair faster as I use the cool shot on each curl as soon as it's off the curling wand.
The attachment works really well but I don't use a brush with the dryer, I just run my hands through so I don't use it all that often.
I don't really feel like it's all that quiet like the description implies, but this dryer really does save me so much time and the noise doesn't bother me.