Several of us have added Vortex Generators (VG's) to the upper wing / fuselage
juncture area on the Genesis 2 and found very good results. As I understand it,
the VG's, placed near the high camber location, cause the local flow to become
turbulent, but the "turbulent" flow reattaches and prevents complete
separation. Anyway, I am able to thermal 5 knots slower and no longer feel and
hear flow separation.

The VG's are 1" long X .25" high and .25" wide (base only) the vertical web is
about 1/16" wide. We place them in pairs that are angled in about 30 degrees to
each other. The hot set-up seems to be 3 sets on each side with 2 on the wing
and 1 on the fuselage. I have seen similar things on a Nimbus 3 and wondered if
they worked. I could play a tune on my Nimbus, by just moving the flaps up and
down, so something bad was going on back there.
The VG's work on the Genesis 2.
JJ Sinclair