I own a Orvis Helios 3wt. The rod is 8'4" a 4 pc and I got the "Mid Flex"
It's the lightest rod in the world! I simply love that rod, and I don't seem to use anything else.
A couple weeks ago, I caught this mid sized approx: 8lb carp with this 3wt. I had a 4X leader on with good knots. No problem, a wonderful thrill with a light rod.
I used to only use a 1wt. I only fish for 'gills and small stream trout, so I like a rod that has a bend when a small fish is on.
I have nothing to do with Orvis, but I love their top shelf rods. When this water goes down a bit, I think I'll get a Helios 2 in a 7wt? I agree with Nick, the 7 wts are underrated!
All fly rods are not the same, by any means. If you have a passion for fly fishing, I'd say get a good one! The Sage "One" is also a good rod? But IMHO I think the Helios is the best available today!