As a hobbyist rod maker, I'll say that there are some good features to uplocking reel seats, but most of them aren't designed/built as well as they could be. On smaller, lighter, especially shorter rods, the inch and a half or so sticking out at the butt reduces the rod's useable length (the part you are casting) by too great a percentage. The same amount sticking out of a stiff nine or ten footer is far less noticeable, and may actually serve as a useful addition when fighting big fish. With greater standardization in reel feet dimensions, there is no reason smaller seats couldn't be significantly shorter and still give plenty of clearance for mounting reels. The other major flaw is the buried hood. Except on really heavy rods, there is no reason there has to even be a hood, since a simple ring, no thicker than the typical trim ring, is more than strong enough to hold a reel. The reel is held in place by the lower ring, anyway. Getting rid of the buried hood means you don't need a cork ring that's hollowed out (thin), and gives the builder the option to reduce the cork diameter at this point, producing an ergonomically superior grip. My own reel seats consist of a cork barrel (of the best cork I can find) just over 3 inches long, with a tapered upsliding ring (to sit flat on both the cork and the reel foot and not dig in), and a trim ring just a little larger in diameter than the cork seat. The cork is flattened along its length where the foot sits, with the flattened area extending under the trim ring. I relieve the bottom grip ring very slightly with a Dremel tool to allow the reel foot to slide up under the trim ring (this is hidden by the trim ring). The weight of the reel and the tapered sliding ring hold the reel in place solidly without putting too much pressure on the cork, and I can make virtually any grip shape I want, except for one where the cork tapers completely into the seat.
-CC