The main difference between stainless and blued guns will be answered by how the gun is used. Bluing is actually a form of introduced corrosion to the metal, but not like corrosion in the sense of rust. But like rust, if you rub blued metal with something for long enough, the bluing will come off completely, showing bare metal. Holsters will do this with continual use. You'll see it on guns that have spent most of their life inside a holster. Stainless won't rub off like bluing will. So in cases where the gun is holstered, the stainless will look the same for a significantly longer period than the blued gun will. Blued guns will also have a tendancy to rust on their own. Leave a blued gun in a basement without any oil and you'll see surface rust in a matter of months, whether the gun has been used or not. Grab a blued gun with your bare hand and leave it alone for a few months and you'll see surface rust form where you touched the gun because of the moisture and salts of your hand. If you drop a blued gun and put a scratch in the finish, it will be that way forever unless you introduce bluing back to the scratched area. Drop a stainless gun and put a scratch on it and you can generally buff and polish the scratch right out. I'm not very good with metalurgy, but stainless has less carbon which makes it more resistant to rust. I have for a fact seen cheaper grade stainless actually rust and I was told that because it was cheap stainless, it had more carbon content which caused it to rust more easily.
As to "prettier", that's all the in eye of the beholder. I've got a Python with a perfect Royal Blue finish that will put any stainless gun to shame. Not all bluing is the same. My first 1911 was a Taurus with a blued finish. That gun has a very poor bluing and it would surface rust within a week if not kept with a sheen of oil. Put that gun next to the Python and you'll see two totally different finishes, even though they're both blued.
The stainless is "prettier" than the blued. Are there any advantages of stainless over blued? Will it last longer? Or is it just for the looks?
