I agree with Larry, that there is a difference between lines. Especially when it comes to price. I have used some of the less expensive lines/cheaper lines, and have been less, pun intended, impressed. The more you pay for a fly line the more you get. Larry mentioned what those are.

I think if you stick with the well known companies such as Rio, Scientific Anglers and Cortland, you can't go too wrong. Even some of there less expensive lines perform well. An example would be SA's Headstart. I use it on my 6wt for warm water and it not only cast well, but also turns over larger flies well.

Normally, what I have found in less expensive lines is that they just don't float as well, or cast as easily as some of the more expensive fly lines. Beating around a bluegill pond may not make those qualities that big of a deal, but it does, at least to me, when I am trout fishing spring creeks, or throwing top water poppers to smallmouth bass.

Dave