right-angle finder for R cameras -- does it work well?

[pgs@pa.dec.com (Patrick Sobalvarro)]

I was doing some macro photography the other night (indoors, under
bright lights -- that's a nice thing about macro: even if it's dark
when you get home from work, there are some subjects that can be
photographed on a table-top).  I was using a Leica "universal
handgrip" as a table-top tripod, which worked nicely.  However, I did
have a problem with the arrangement.  After a bit my neck was sore
from moving my head into awkward positions to look through the
viewfinder.

I was wondering if anyone on the list might have used the right-angle
viewfinder for the R4 and later models, and if you've found it to be
well-constructed and useful.  I've always wished the R cameras had
interchangeable finders so a chimney finder with magnifier could be
fitted -- the right-angle finder looks like it might not couple
securely.  Does it in fact work well?