KidSnide
Adventurer
For puzzles, if the players enjoy puzzles, then the players solve them. If they hate them then we do a Int or skill check. Fun trumps aesthetic concerns regarding system and concerns about "why is my barbarian good at logic?"
This is the key issue. If the players find some aspect of the game unpleasant (because their not good at it personally, because they don't think their characters could do it or for some other reason), then the rules should provide the ability to turn it into a character challenge. If the players find the aspect of the game fun (because they like puzzles or want to role-play out the interaction) the rules of the game should allow them to play it interactively. If the group likes a mixture of things depending on the player (or the player's mood), the game should allow some combination (maybe an interactive section and a large modifier).
What's fun for one group isn't always fun for another. The game needs to support groups spending time on what's fun for them and abstracting away the parts that aren't. What's played out and what's abstracted is going to differ on a table-by-table basis. D&DN is supposed to be a "big tent" game and it needs to support the range of preferences.
-KS