There is a lot of misunderstanding about square / rounded tops. The most important thing is that the sail is cut with a planform, twist and camber to achieve a particular spanwise loading. There is no unique solution to this. If the main top is bigger, then you can have more twist and / or a flatter section than if the main had a smaller top. The influence on drag of whether the top is squared off or rounded is minimal. This is why you can look at 14s, 18s etc and see sails of different planforms all of which perform well.
Clearly the Hydes perform well, and at those prices, they represent really good value. It will be important, though, to make sure that the mast and sail match in terms of luff round. Pete's mast is a lot stiffer at the top than say, the CTech, so a sail for the CTech would need more round higher up the luff.