I have a preference for the heavier reels to begin with. I think they lessen the swing weight of the rod. 4 5/8 is pretty heavy for a six weight (unless it's 10' or more). The weight of that rod would put it up there with the average eight weight or heavier rod, so a 7-ish ounce reel is what it would probably take to balance it. I have an old 10' 6wt. T3 rod that weighs 5 ounces and I need at least a 7.5 ounce reel or heavier to balance it. It's less critical if you're using a small stream rod but when you start getting into heavier/longer rods, it makes a huge difference.