There has been quite a bit of very good advice on this issue. For what
it is worth, having faced a similar decision in the past transitioning
with low hours from club materiel to a private glider (ASW24E in my
case), here is how I see it:
Buy a glider you will be happy to fly. Everybody has their own view of
what this may be, so take the time to form your own opinion. Choosing a
glider is a very personal journey.
A glider, when well-cared for will keep its value, so it will be
realistic to change if you feel after some time that you want something
else. Having said that, it is better to buy what you want now, rather
than move up to it slowly provided it is a suitable choice (i.e. open
class could be tricky as a first glider).
Here are the main points I would like to consider:
You can have incredible fun in a classic wooden glider (and it is good
to remind yourself once in a while by taking a few flights in one), but
if it is cross-country you fancy, going for slick fiber is what you
probably want. Having said that, if you can have access to such glider,
it would be nice to be able to take your first cross-country steps in
one. The confidence one gets with being able to land practically
anywhere with these low-speed low-wing-loading machines is awesome.
When considering old versus new glass, there is some incredible value to
be had in some of the great older models out there (ASW20, LS4, Discus
etc), but you will have to carefully evaluate what you buy. If it is
well maintained and has gel-coat in top condition, do not fear. However,
buying a glider with gel-coat in bad or simply unknown condition could
become a heap of expensive trouble very fast (and would be difficult to
resell at good value).
The good thing with the newer models is that they will usually be more
trouble-free to maintain. It is also the case that most newer models
have a safety cockpit, which to me is a very crucial feature to
consider, as well as other safety-related features such as
self-connecting controls which are harder to find the more back you go.
I would not be fazed by the flaps/non-flaps issue, this is a matter of
style in the models we are discussing (although if flying in areas with
very strong weather it can make a difference). Nor would I obsess over a
few points of L/D. It will probably take quite some time before such
things start making a difference in your performance if at all. For most
of us pilots, what flies the farthest is the glider we feel happiest
flying in.
What could make a difference is the quirkiness of some older models --
although to my knowledge the gliders being discussed here are excellent
in terms of handling. It is typical of newer models (even the hottest
racing machines) in 15 to 18m wingspan that they are a joy and easy to
fly, devoid of strange flight behavior or quirky handling requirements.
What will be different is that they are slippery and much heavier than
what you have been used to flying (even if you have been training in
glass). This means that everything will happen much faster and that
energy management will have to be more precise. There is nothing
inherently difficult or exotic in this. It just takes a few flights to
get used to it, so by all means consider a trip to a site will an
appropriate training fleet as part of your purchase process and take the
time needed to acclimatize to this new environment.
One last thing I have learned the hard way: it is better to invest in
the best trailer you can buy and spend the balance on the glider rather
than the opposite. Your trailer setup will probably have the most
influence on how often you fly, or how far away you dare venture. Make
it a good one.
Have fun and be safe,
Alexander