erm no its not really at all..

i use my gf's 3gs all the time. not much init between my 3g.

the user experience is almost identical, sometimes the 3g can get abit slowdown on larger games, whereas the 3gs can play them better all the eime , thats about it..

in terms of phone/email/gps(bar knowing direction)/txt/most apps hardly any difference worth mentioning at all.

the iphone is still the top phone.. the 3g and 3gs are much more stable in comparison to the nokia n900. but the n900 is a totally different experience- it really does bring out the geek side.