Anybody walk into Apple Retail and exchange 4S for a different capacity?

I bought my 32GB 4S from the Apple Store in Houston on Saturday. First time ATT customer, new sign up, new service, etc.

Now, I'm wondering if maybe I should have gone for the 64GB. I reserved a 64GB last night for pick up today.

Should I be expecting any issues from Apple and/or ATT for simply wanting to exchange for a larger capacity (obviously I'd be paying the difference in price)?

I bought AppleCare+ along with the 32GB on Saturday and so I'm guessing that they will probably just process the whole thing as one big return and then create a new purchase for the 64GB and new AppleCare+.

I shouldn't expect any restocking fees and/or having to pay another ATT activation fee, correct?

FYI, the return/exchange was easy. Brought in the iPhone with all accessories and box and told them that I wanted the 64GB. They said no problem, deactivated the old phone, activated the new phone, charged me the $100 difference in price and sent me on my merry way.