Stainless has a lower tensite strength and is more prone to a barrel splitting from ovstruction, etc. Anyone remember all the SAKO fluted barrels that blew up? All stainless.
Stainless is a perfectly adequate material though if machined and heat treated properly. It WILL rust - I've seen it countless times. It just RESISTS rust more than cromoly barrels do. Don't believe me? Ask your gunsmith. Alot of guys figure it's rustprrof and don't clean after rain for weeks while the gun is cased. They get nasty surprises when they open those plastic cases...
Personally, I much prefer blued steel - but if I lived in a remote area where I was really going to abuse my kit, I'd likely have at least one stainless gun for long treks in wet weather.
In terms of wear, you won;t notice any difference - I'm quite sure.