I've flown only the '24 but against quite a few '28s. No discernable
consistent difference in performance so long as the '24 has modern
winglets (see UH about that). '28 has more cockpit room, but my '24
has the factory mods for tall pilots (higher cutouts for the knees,
etc.) so no problem there. I'm cynical about the whole microturbulence
thing: I've always thought it was a marketing ploy to transition '24
owners to the '28, or to explain away the early '24s that didn't
always climb/handle as well. Modern winglets take care of that.
I've kept my outer wing with the early '24 sharp leading edge because
I can climb with anything already and always fretted that the "B
mod." (as the blunter outer leading edge is referred to) might cost
some high-speed performance (only in the U.S. Presidential elections
are we promised something for nothing). Others say not but I'm not
inclined to tinker.

Reasons to buy a '24 over a '28: 1. The '24 has perhaps the most
stable wing of any modern composite sailplane. Sand it if it makes you
feel good but the contours just don't budge (mine is 16 years old and
I run the gage on it every year). I'm told the '28 may be more like
the '27 and '29 (i.e., the contours move around a bit the first few
years) although, since I don't own one, this is just hearsay. 2. Lots
cheaper.

Reasons to buy a '28 over a '24: 1. Newer gel coat, trailer, etc., and
2. hard ballast tanks. But I haven't flown with the factory tank
system so I can't compare it with the rapid dump I get using 1" ID
plumbing all the way through or the ease of filling.

Chip Bearden
ASW 24 "JB"
USA