Marfa Task areas & directions

I am planning a trip to Marfa TX for next summer.  Several pilots in
the group want to attempt long flights, including some FAI length O&R
and Triangles.
300km, 500km, 750km and 1000km lengths.  These lengths put you over a
lot of ground.

I'd like some advice from experienced Marfa/Hobbs pilots on which
areas, turnpoints and directions offer good soaring, better landout
areas - especially beginning and end of day.

Most importantly advice on areas to avoid.

I thought of looking at some of the contest tasks that have been flown
out of Hobbs but that is a bit away and I would not know what the
pucker factor was as the pilots overflew some of the areas.

thanks
Chris