When I had the Claro, it would auto-adjust depending on noise levels. It actually drove me out of my mind in high school, with switching classes (the noise in the hallways would trigger the auto-adjust, switching to the noise setting, but it'd switch back to normal, noise, normal, etc... within seconds). I had the auto options turned off later on, preferring to change the settings myself when needed.
Phoank has some neat features for their hearing aids (and for the Advanced Bionic's Naida line of CIs), such as feedback control, echo block, wind block, zoom, auto zoom, etc. I think with the Phonak hearing aids, you can also adjust the settings on one aid and it'll automatically adjust the settings for the other aid, and both aids will communicate with one another (if you were to use the DuoPhone feature, you can hold the phone up to one ear and the same stuff you're hearing on the phone will automatically be picked up by the other hearing aid, giving you bilateral hearing aid when using the phone). I use some of these features with my CIs (DuoPhone, Windblock, can't remember what else I have added). I like what Phonak has been doing, technology-wise, for their products. I can't say what the other hearing aid manufacturers are doing with their own line of products or what sort of technology and features they've developed.