Ard is correct; it's more about the individual than the rod. Some like really fast rods for dries, others don't.
However;
My favorite sub-$600 dry fly rod is still the Winston GVX (or GVX Select, which is the same rod with some red rings on it). Medium-fast action, on the 'medium' side. "Buttery" is a term used a lot when describing the action. I don't know about that, but it's extremely smooth. Mine's a 9 foot 5 wt., but I'd bet a pile of money the 8.5 ft. 4 wt. is the Excalibur of dry fly rods for people like me.
Unfortunately, Winston stopped making them a while back, and apparently everyone that bought one loves theirs a much as I love mine, because in spite of searching every summer when it gets too hot to fish, I haven't found one anywhere. I've even gone back to the fly shop where I bought my first one, because they have a 'buy-back' program, and they always have some rods that are hard to find, but no dice. I told them to call me as soon as they get one in, any GVX rod, and I'd almost certainly buy it. That was 7 years ago now. Crickets.
Anyway, good luck in your search, and I'm sure you'll get lots of good suggestions. Probably have already.
Me, I'm going to have a short glass of Ardbeg's Crorryvrecken and dream about finding Excalibur on my next fishing trip . . .
Peace.