If I aged, I'd want to be Mortal. If I aged and I was Immortal, I wouldn't be able to do shit (Moving, Shitting by myself, wearing Adult Diapers, ect). If I didn't age, totally Immortal, just because I'm awesome.
Immortality has so many problems... Sure, you could live forever. But why? First, which is stated here is the problem with aging. If I can't do anything in 100 years why bother? Another is everyone you care for will die.. I mean, do you want to go through all that, all the time? Also, what happens if the human race dies off? You're going to be alone, forever...
Sure, immortality, but I'd like a way to kill myself.
You are able to die by someone killing you... and what if the ones you love are immortal?