I am surprised no one has mentioned the Orvis Hydros? It is just like the helios, but with lower cost hardware and a $495 price tag.
Great call! The Helios is one of the best rods out there, and the Hydros is a super value, relative to the Helios (offering Helios performance at a much less cost). With that said, there isn't anything out there that is as light as that Helios. Orvis is a super company, too, and our local shop has some incredible people working there that will provide you great customer support.
I have to agree with the bulk of the folks on here, that you should cast a few rods to see which you like. Ideally, they should be side-by-side, with the same line, so you can get a true comparison. If you have a decent 5 wt line that you don't mind bashing on the asphalt (or may consider that you need to sacrifice a line to find the 'right' rod), take it with you when you cast the rods.
I do disagree that the lower cost rods cast as well as the higher priced rods; generally speaking, I don't find that to be accurate. HOWEVER, do the upper-end/higher-priced rods perform that much better to justify the cost? That's for you to decide. A whole lot of fish could be caught on a piece of fly line attached to a stick, but I woudn't want to do it.
Any top of the line offering from the big guys, like Orvis, Sage, Loomis, T&T, Winston, S,t. Croix they're all good. Redington, TFO, and Echo offer rods that are excellent performers, and are bonafide deals given performance per dollar. I'll get shot for this one, but the top of the line Cabela's rods are excellent, too.
Here's a sleeper for you, though. If you like St. Croix, the Legend Elite they offer is an awesome rod. I think it's one of the most under-sung values out there. It's performance, quality, and hardware is on par with the best out there, for under $500. On a work travel trip to CO I had a couple of hours to spare before flying out of town. I stopped at a local shop and cast a few sticks. I cast a Sage VT2, then a Legend Elite right after, and I couldn't believe how 'clunky' the VT2 was compared to the Elite. The Legend Elite reminded me of a Z-Axis, which is arguably one of the best 5 weights out there.
Go have fun shopping and casting!