I have flown an SZD-55, an LS-4, and have flown with and against
LS-8's and SZD-55's in competitions and on long cross-country flights.

If they're in comparable condition and price, get whichever one has a
better trailer and/or better gelcoat! Seriously. Everyone that talks
about the importance of a good trailer is speaking the truth - a
clamshell (Cobra, Avionic, Komet, etc) in good condition is worth a
lot - in that it saves you a lot of hassle rigging and a lot of
maintenance issues that a bad (or leaky) trailer can cause.

On the aircraft: Both are really great ships and its hard to go wrong
with either one of them. The SZD-55 will do better in light
conditions, as has been noted. Its no slouch in strong weather, but
the LS-8 (IMHO) will be better in strong conditions. The older LS-8's
may or may not be subject to the DG fee (DG took over LS ships); but
speaking as the owner of a DG-300 I only pay the fee if I need factory-
original parts and have no other recourse. I've owned my '300 for
several years now and never paid the fee (of course, my '300 is also
registered experimental which gives me a little more leeway).

My biggest advice: Don't rely on pictures. Its very hard to get a
sense of a glider based on pictures alone - you HAVE to see it with
the naked eyeball. If you're going to spend tens of thousands of
dollars on an aircraft (and many more thousands to maintain it over
the years), do NOT cheap-out on inspecting it before you buy it! If
you're looking at a glider that isn't local, check it out and do a lot
of homework - then if it still looks like a good deal buy a plane
ticket and go see it for yourself (in addition to having an A&P do a
pre-buy inspection either before or after this step)! I flew to look
at 3 different aircraft before buying my DG-300 and I am *so* glad I
did... The extra $1500 for those trips has easily been made up for by
not getting an aircraft I regret (or have to do extra work on).

Good luck!

--Noel