I have a 16GB purchased on iDay2.
I do not have any real problems I guess.
I have very very very slight light leak on the left hand of the screen. For the most part, I am not even sure if it is real light leak since it almost looks like slight pin pricks on the side and almost looks like a slight reflection from the bright screen itself on the chrome bezel. I can only see this in a pitch black room and if I move the phone this way and that. I will keep my eye on it especially if I get any dust-- but I am not at all unhappy and with the case on it I cant even see the bezel at all so....
Other than that, I dont have any scratches, dead pixels, dust, etc. The apple symbol on the back is perfect, my screen super bright.
Now-- software wise-- well there is some definite instability. I have a tons of apps I downloaded so maybe that is it but I do have from time to time the slow text typing lag and I do have apps crash--- although none of the apple apps crash.
Other than that-- I am very happy. I sold my 4gb iphone on ebay for 300.00 so I feel like I definitely made out well. It is faster, tons of space (for me at least), and beautiful. I do wish my 3G signal was a little stronger, but I have not had any dropped calls at home where this seems to be more of an issue. At work my 3G signal is very strong so I can live with that since at work I need the 3g since I am not allowed to go on the wifi with my phone and at home I can use my wifi-- so.. eh a good compromise.