Gear is the joy/bane of our sport, the love/hate of the relationship. We always wonder if the next latest and greatest offering of the gods of industry will be the answer to breaking sixty, seventy, eighty, _______ feet on our cast, and finally reaching that far bank for that fish. Yet inside we know the truth, we'll get past sixty feet when we find time to practice... practice a lot. My friend Alex Ramirez reps for Sage and has worked retail in fly fishing for years, helped me in the wording to communicate clearly, some of the concepts, and keys to finding a fine rod. It's nice to have a perspective from someone who has had to try to find a rod to fit an angler wanting to buy a rod.
I think the best reason to buy a new rod is for a new river or trip, maybe to pursue a new species or larger fish, or perhaps a casting discipline like Spey. But in my experience there is no technology to correct bad technique. I would suggest you spend some time and money on improving your cast first, and then watch what a rod can do. You may honestly out perform it's capacity. When your fundamentals are sound - the pause, the arc, the path of a rod during your cast - then, the type of action, the feel, a rod has starts to make more sense. Let these factors be your guide to a purchase.
A rods action - it's stiffness or time of recovery - is termed ultra fast, fast, or mid/fast action. The rods action fits into the context of how you cast, what you fish for and how windy the conditions may become. A mid flex-mid/fast rod works to a person who has a naturally long pause and a gradual stroke, who likes to dry fly as well as toss a light indicator rig and fishes in little to no wind area. An individual with a fast pace and a quick stop, who likes to throw a streamer in big water, multiple indicator rig, and larger dries, will do better with a fast action rod.
There are a lot of great rods at very affordable prices, all have great tapers and adequate fit and finish with the majority of the manufactures offering a lifetime no fault warranty (when you accidentally snap the tip in the car door). High end rods are going to have nice hardware and finishes as well as the latest taper designs and marketing to drive up the cost. Rods do cost a lot, so go to demo days at your local shop and cast away, cast your buddy's rod, then cast some more. Then, please do go back and buy it at the local shop, the pricing is all the same. These folks have some skin in the game, they like to see you back in the shop, to a web site, you're just an I.P. number! Above all, do your homework, ask a bunch of questions, cast it a bunch, buy it, and then, get out and fish the resin off the thing!