I am one of the early Bold users (if I can say that) and can tell you that the latest OS is eons better than the stock OS that came with the unit when I got it. I am not sure if it is carrier grade or not but it suits my purpose just fine. I love my Bold and can tell you it's been the best BB I have owned ever. I even contemplated going with the iPhone at one point but given the severe restrictions with Activesync, I cannot see how I'd ever get myself to going with it (at least for now).
What it finally comes down to is price. If you are willing to pay the full premium to acquire it now or wait till AT&T releases it and buy it for a lower price.
My 2 cents.
9700 on 6.0.0.something, BES 4.1 on Exchange, BIS (AT&T)
Ex 8700, 8800, 8100, 8310, 9000