I have a very recent vintage T400 - the keyboard is still mushy, and the casing still feels downright cheap and flimsy. There's simply no comparison - on the one hand you're building a machine out of plastic panels wrapped on a metal frame - on the other hand you're building a machine out of a one-piece aluminum construction.

I push on a unibody Mac keyboard - nothing flexes. It's rock solid. I push on a T400's keyboard, or bezel, or any body component that isn't supposed to twist and bend - and it does.