I think the difference is between 1 and 3 degrees. This is just a guess, however.
It does mean something, but not much unless you're racing.
I've been close-hauled in winds gusting over 30 knots. I furled the genny, hanked the staysail onto the inner forestay, and put a reef in the main. She sailed at about 4.5 knots and around 10 degrees of heel. It was a walk in the park. She also pointed higher than with the genny, due to the better sheeting angle.
I don't think there's one right answer on the keel. I like my shallow draft - even though it can't protect me against all my stupidities, it does mitigate some of them. It would make sailing the intercoastal or around FLA a lot easier if I was down there. If I owned the deep keel, I'd probably tell you that it's only a little deeper and makes less leeway, so ...