Condition matters, but it's usually more an economic factor than
performance. Removing/refinishing bad gel coat costs much more than
you will likely get from the glider when you sell it. It's better to
buy a glider with gel coat that will last for a while. Upgrading
instruments can be expensive, depending on how far you want to go.
Trailers deteriorate, too, with some known for having weak points
(e.g., late 70s Komets where the axle attachment points fail and the
axle pushes the floor up) though those problems can usually be fixed
with a modest expenditure of time and/or money.

Some glider finishes do seem to deteriorate faster than others but
you'll already be able to see what's good and what's not in a glider
that's 20 years old. Some will have been refinished once. Some may
have done better than others: e.g., those with a painted finish (e.g.,
PIK 20) and DG.

As concerns performance, some gliders do suffer more than others from
airfoil inaccuracies: the section used on the PIK 20/Mosquito/Nimbus 2/
LS-3 and others is an example. The LS-3 (which I owned) develops flat
spots where the spar cap shrinks; if not filled, the high-speed cruise
is affected though the climb is still good. The wing on the ASW 24
(which I own now; not on your final list, I know, but a superb value),
on the other hand, seems absolutely timeless regarding waviness.

Regarding pilot height, the parachute and torso/leg length ratio can
have an enormous influence. I'm 6'3" (191 cm) with, apparently, a
relatively long torso. I need a chute that's very thin behind the
shoulders so I can recline as far as possible. Most chutes are
constant thickness. Before you cross off a glider from your list, try
different parachutes first. Try to borrow a Softie Wedge or Strong
backpack, and I think National now makes a similar one that's thin at
the top.

Don't get obsessed with performance. As others have said, piloting
counts for a lot more. Buying a sailplane IS a major investment so
approach it that way: think "value" and resale and you'll be fine.

Chip Bearden
ASW 24 "JB"
USA