Some very valid points in the last post. But with any gun, if is making a good spray pattern, you should be able to paint metallics with out "tiger striping".
I am going to suggest the biggest factor is still how the gun is handled. I have seen posts about painting that ask "Why do I have runs and orange peel in the paint I sprayed?"
Reality is, if that happens, you were spraying too wet in one spot, causing runs, and too dry in another, causing orange peel.
If you can afford it, buy the higher priced, high quality gun.
But if the price of a gun is holding you back from buying any gun, I would suggest you can get a good paint job without a high dollar gun.