I've got one & I love it, I had an n95 before that but had to keep returning it as it kept crashing all the time it was A great phone tho.
I certainly wouldn't think of going to anything else now I've got my iphone.
It depends what you want it for, I use mine a lot for work & the email functionality is amazing also the ipod & video playback are awesome but the best think about it is the internet access (which is free on iphone contract)
If you want it for camera however go for n95 as iphone cam is a bit crappy.
Just remember apple are constantly upgrading & adding new apps & features to iphone & this doesn't happen with any other unit.
Know what you mean about apple upgrading all the time but do you think there upgrade to firmware can alter the cam? I really just dont know what to do to be honest as i am sick of my N95 it crash on me too and it gone away for repair at the moment as the left soft key has broke now....
The camera can be altered slightly with updates for sure as there is already an app for jail-broken iphones which I have used i think its called "camera pro" & it adds zoom feature, multiple bursts, self timer, color changes & other things, (why apple didn't include this from the start I have no idea) so apple could integrate these features in future updates, however the fact that the cam is only 2 mega pixels cannot be altered as this is the camera hardware itself so the picture quality I don't think can ever be improved without replacing the camera.