It's not the OS. It's the fact that there are probably a few million people still trying to download/install at the same time. I had the 3184 error, but that was only because Apple was getting slammed.I'm considering staying with iOS 5.1.1 until I get a 4s. It's just that iOS 6 seems a bit buggy.
I'm with you I still have a 3GS also, I will wait for at least a month before I upgrade it. I also have the first ipad I may wait on that upgrade too.I have a 3GS and I'm thinking this is the last OS that will be compatible with it. I'll probably upgrade to a 5 this winter when all the hype is gone. Also waiting to install new OS until the bugs are fixed