Well, too late.
I was a more or less happy customer of RHEL for 2 years, with 4 licenses of RHES3. The distribution was rock solid, but the RHN was a mess, rarely worked the way it was supposed to, updating only some of my servers, and the performance was painfully slow.
I dropped RHEL and moved over to CentOS, not because of price (I believe they should be payed by their services), but because the software update service was better, '''way''' better than RHN. I've dropped CentOS paypal account some cash, also. Good things should be encouraged.