I'm kinda forced to aggree on the New Orleans from my own experience - I also don't find it a very enjoyable ship to play at this time. It pretty much feels weaker than the Mogami in every respect except AA (although the gun buff coming in the next patch is supposed to make USN 8" AP very good, so that might help slightly offset the insane IJN HE shells, but I still don't see it outgunning a Mogami against most targets except maybe a broadsiding cruiser at short range but those are kinda rare...), and AA is useful in something like a third of all games because either there's no enemy carrier at all, or he just goes to torp a different part of the team than the one I'm with (admittedly that is also a contribution to the team via keeping a part of our force safe from that strike, but certainly not a fun one for me). And it's not that I would be doing totally atrociously with it, 45k average damage and a positive KDR isn't too bad, but it's just not that much fun for me at the moment.
Other than that I wholeheartedly aggree with the OP - understanding how your ship is supposed to work is a key part of both doing well with it and having fun with it. And that's a sign of a well working class-based system, even if there are a few balance kinks to work out (which there always will be, and that's not a bad thing!)