RedHat has made an excellent decision when using the RedHat-network stuff... the update checker, so no comments there.
But on the other side, people that aren't used to Linux (in general) will have problems installing/adding software. The rpm system is nice, but If you can't find an rpm that's compiled for your exact system, you're in trouble. And let's not forget the infamous dependancy hell!
So why not use apt-like system (I'll call it apt from now on)?