iPhone

You know I just do not understand the iPhone anymore. I have the 3gs and it has already been replaced once not only for the software but other issues also. Now the thing is locking up, closing out on applications, going really slow, etc. Shall I go on?? I thought about getting the 4 but now I am sure glad that I didn't and I think I will wait awhile before considering buying another iPhone. It is just so frustrating to me as I am so not patient....besides - I don't even use it like it should be used....should of saved my money....lol.