I'm a fan of steel frames, so that's my bias. It just rides better than aluminum - especially earlier aluminum frames. It's also supposed to be more durable over the long run (assuming it's kept from rust.) The assumption is that rust is less prone to bend like steel is and will fail catastrophically after a certain age. I've never heard of that happening in the real world, but that's what the "experts" say.

That being said, the colors on the Centurion. 0.o eek!

I like the colors on the Trek & the fenders would be nice for a commuter. I'd be torn, honestly.