Stainless is sold primarily as a "poor man's titanium" with the primary benefits being corrosion resistance, that paint is optional (which is nice in a city or utility bike), and the ride is familiar to those who ride other steels.

To the best of my knowledge, there are three stainless tubesets commonly used in bikes: Reynolds 953, KVA and Columbus XCr.

There are many differences between the three as a result of different alloying, tubing sizes, butting, and wall thickness. Some is even said to rust. And some is magnetic. There's a brief discussion of some of the differences between them here.

Since there are many different chromoly tubesets as well, it's not really appropriate to make a blanket statement about what you're paying for. "It depends on which chromoly and which stainless" is the closest you'll get in any answer that's reasonably truthful and knowledgeable.

Ride-wise, it's probably better to compare stainless to the high-strength air-hardening tubes like Reynolds 853 and True Temper OSX. (I ride an 853 bike and don't particularly care for the springiness. I think it adds a kick to bumps that I don't get on my other bikes. Other people think it's the cat's meow. YMMV.)

But most people buy for the corrosion resistance. Some still paint it--they just don't want to have to treat it with Framesaver every few years.

EDIT:

I *can* tell you that the second-hand Litespeed I bought a couple of years ago has become my favorite knockaround bike since I don't have to worry about paint. I run errands in the city with it because locking to signposts won't hurt it. I take it on rides with my ride partner since all I have to do it throw it in the back of his pickup. No fussing with racks. Hell, it even looks better with a patina of dirt on it. In short, I can treat it like a bike.

If you're considering stainless for that sort of use, I say go for it. A bike that doesn't require paint is a liberating experience.