Better acted, yes. Better written? That's much tougher.
Whedon is wittier and far more entertaining, but pretty much runs at breakneck speed with little room for more somber, delicate scenes. Nolan's script is heavier and captures the gravity of the situation, but can be ponderous and boring.
I'm inclined to say it's a wash. Both have their strengths and both have their flaws.
But acting, yeah, I'd give it to TA all day. Ledger is the standout performance by far in TDK, everyone else is incessantly grim and one-note. Bale has all the depth of a contact lens. TA is a much stronger and more dynamic ensemble.