I think this really depends on what you're looking for. I've had a 227 Tac Ops for a year now so I'll offer my take on that gun. I've put something like 600 rounds through it, hollow points, cheap stuff, etc etc. No malfunctions. It's very accurate as well (not that that needs saying about a Sig).
I do have a few criticisms. While I can appreciate the extended magwell grips in the tactical role, they didn't work for me so I picked up some Hogue G10 grips (which I love). Additionally, I'm very mixed on the fiber optic TruGlo front sight that Sig puts on the Tac Ops. I love the fiber optic and how bright it is, but recently the fiber optic came loose. While this certainly doesn't render the gun inoperable, I expect better out of a $1400+gun. I called Sig and they sent me a new front sight under warranty. Whether you blame TruGlo for bad manufacturing or Sig for selecting a bad sight doesn't really matter, the sights are the last thing I should have to worry about on the Tac Ops. Outside of that, I love the gun. The SRT is great, I like the beavertail (despite claims that it doesn't do anything on a Sig, I still like it). The front serrations are nice if you like that sort of thing. To me, where the Tac Ops sells itself is as a complete package. You get an awesome gun with effectively a full combat load of magazines, and the bragging rights of buying the nicest possible 227 (if you like bragging rights).
My opinion on the P220 Legion doesn't matter much, but given the chance to choose right now between a Tac Ops and a P220 Legion, I'd still go Tac Ops. Fits my needs better.