I enjoyed the Reach campaign, but always felt like it suffered from feeling more like a 'Halo: Greatest Hits' collection rather than it's own thing. You've got the bit that's like the beach landing from Silent Cartographer, the bit that's like the sniper section at night in Truth & Reconciliation, the bit that's like the city fighting in Outskirts, etc, etc.
That's actually how they designed the game. Lehto wanted to revisit all the level styles they had done well, and put in the ones they really wanted to do that had to be cut from 1/2/3.
The only one had to kill again was a beach landing level with watercraft you could pilot (which Lehto had been trying to get in since Halo 1) and one where you pilot a Scarab after New Alexandria is destroyed through it's ruins.