Thing is...
Bottom line, the Sig 220 probably is the better gun in at least one way that matters to most people.
However...
To compare the two is just a bit inane. Of course the Sig is at least marginally better according to most people, it's much more expensive.
I like my XDs much better than the Ruger P series, but the XD is a slightly better and more expensive gun, of course it's at least marginally better. But as far as function goes, if you'll adapt to it, the Ruger P series will realistically do everything the XD will. You could pretty much make that comparison to anything though, such as the Sig.
The fact that the Sig costs an arm and a leg is the reason something like the Ruger exists. That doesn't mean the Ruger is bad or vastly inferior, just that it's not really comparable.
Then again, I sold off my Sig and I still have a Ruger. So it's not necessarily a question of which one is better, it's which one is more appropriate for you and your intended purpose.