I think you are jumping to too many conclusions. Cats and tris sail very similarly, except for tacking -- the tris tack more like monohulls. Heck, they are light monohulls with training wheels! <img src="http://www.catsailor.com/forums/images/graemlins/smirk.gif" alt="" />
Both cats and tris are built to be light and fast. That lightness causes the boats to lose speed through the tack, unlike a keel boat that carries momentum through the turn.
Jibing a cat and tri are very similar.
Tacking a cat takes more technique than tacking a tri.
Rick