Except a lot of the fun discussion of CharOp was pointing out how it did add a lot of interesting options to the game as a whole.
As an example, Defender|Defender. Every last Defender|Defender combo is workable provided you fix AC for Warden & Swordmage and realize you don't absolutely have to have an 18 in every primary stat post-racial, especially for Battleminds+Str Classes. And that's because as a default, they all have the option of multi-marking in exchange for the superior single class lockdown of their mark.
That's often a very fun subset of the optimized game - doing multi-marking, but unlike the optimized game, you don't then by definition fix for lack of lockdown because you don't necessarily realize how to do it. For someone who likes Defender, this then opens up the realization of just how important positioning can be.
X|Leader can often solve the very common problem of "No one wants to be the healer of the party, but we all want someone else to do it."
Striker|Tough Class+Fix AC can often solve the problem 'Player Y doesn't know what he's doing and always wants to play a glass cannon.' Sorcerer|Cavalier(or Paladin) with Paladin Armor proficiency.
Etc...
