I've only heard one station in two of the past three SO-50 passes i've worked and most of them covered the East Coast. The last pass had no one else on at all and was 15 degrees elevation in New York City (8 degrees in California). I sent out a dozen QSL cards from my trip to CM99, and the majority were on SO-50, so there are usually people there to work (just not much in the past two days).
On the other hand, AO-51 has been quite busy on the transcontinental passes and has been hard to get into. SO-50 isn't hard to work if you have an AZ- EL mount and works well hand-held with an Arrow (or equivalent), albeit a bit hard to find when it's so quiet. Both use a 67 Hz PL and there's often someone to turn it on if you don't know how (and it's not hard).
73's and catch you on the birds.
-- KD6PAG (Networking Old-Timer, Satellite QRPer)
[Note: I never send unsolicited binary attachments and if you receive anything purportedly from [email protected] or [email protected] that isn't signed with my callsign, then it probably isn't from me. There seems to be a new virus or worm around, so beware.]