I've found that with congenital problems with both knees and hips, that have resulted in severe arthritis, and the replacement of one hip after it had fused... Horizontal top tube frames no longer have the appeal that they once did for me. But, really looking back on it, I always thought that the "Standard" diamond frame bike was pretty boring aesthetically anyway.

I ride all types of frames now,(step through, diamond, semi-recumbent) but my favorite is by far my Mixte (so I have twin angeled top tubes)... Which got me interested in the old cross frame designs of the late 1900's through 1950's http://www.rijwiel.net/kruisf2e.htm I would love to have a Utility/Xtra cycle bike based on the old Locomothief Frame design.

But, I guess you all are just talking about "Road Bikes" which I'm really not interested in anyway overall (even though I used to own several).

I just have to laugh, because it happens in C&V forum as well... When ever anyone starts talking about angeled vs. Level top tubes, it turns into a virility comparison contest, or something. "Huuurumph I don't need a slanted top tube, I can still throw my leg over a level top tube Huurummph huuuurmmmph"... Like that has something to do with it.