To all of you that have had you 3G for awhile. How is the back of it holding up? Is it getting scratched up bad? Does it scratch easily? I am thinking about getting a 3Gs which I assume will have the same back as the 3G. I would also like to know if the 3G has more grip than the original 2G. I find the 2G to be very slippery and would like to know how it compares to the feel of the 3G. Thanks for any help!