Janus 2-seat glider as a club glider?

Depends on what you want to use it for. Ab initio: no way. Advanced
trainer: not ideal. As a cross-country trainer it is well suited. Flaps, so
a bit more complicated to fly than other sialplanes for some pilots.
Relatively high landing speed. Forget about the drag chute (it works about
50-50 chance). It is a pig in maintenance in a club environment, especially
above 3000 hours. I had one that was on its 3rd set of wing-fuse pins, 7th
set of stabilizer attachments and play on controls was a constant issue.
The ironwares on Schempp-Hirth are disappointingly low quality, alas.