The Virus/Sinus are low performance and the view out when thermal
turning is appallingly bad.

The bubble canopy Taurus is better and in strong conditions seems to
go quite well, plus it has a Rotax engine not that heap of junk Solo
found in DG800x & others. You'd struggle to call it high performance.

The DG400 has the usual DG self collapsing U/C feature. Once you
know about this design triumph it's easy to keep the U/C in working
order. It's nice to fly and has really good performance in strong
conditions; the view out is excellent. The engine parts (at least in EASA
land) are not a problem and it's a Rotax not a Solo and it doesn't
regularly break its drive belt. The gel coat/finish is excellent, as usual

with DG. Dealing with DG as a company was a joy. The engine
management man/machine interface is very last century; if you have
three arms you will have no problem, it's nearly as bad as many current
turbo/self-launch gliders: plenty of scope for finger/brain malfunction.
The 400 wing section does NOT like rain or bugs. One of the four
Hoteliers (flaperons & air-brakes) is a tricky blind fiddle to fix &
secure.
Vibration related failures are a known issue: that said my "400" was
significantly more reliable than my much newer Solo powered DG808C
or my Antares 20E.

My choice would be a DG800A (basically a 400 type fuselage/Rotax
engine + DG800 type wings). It doesn't like rain or bugs either but is
significantly better than the DG400 as a glider.

I think all newer DG800x have a vastly improved "one-switch does it
all" engine management system that really is very good?

I've got lots of hours in someone else's Stemme S10, the Limbach
engined one, it was very reliable but the VP propellor overhaul costs
were eye watering even 20 years ago. It's a very competent glider but
big and heavy, not at its best scraping low on the rocks.

I can't think of anything polite to say about Wankel engines... a
vibration free engineers nightmare?

If economics are at all an issue just buy a proper sailplane and get a
tow: it's a FAR FAR cheaper way to fly.