Garmin 60csx works good in my living room on the couch, while I upload/download maps/waypoints from my laptop.
Conditions:
the blinds are closed on the windows which are about 10' away
there's 2 3'x4' skylights at about 4' and 12' away (and 12' up on vaulted ceilings)
there's more windows behind my about 20' away, but behind the couch and no direct line of site
FYI: stucco exterior with clay tile roof and 5/8" type X sheet rock interior
Reception:
gps just turned on 3 min ago
10 good satellite locks (03,07,09,14,15,18,19,21,22,47)
9 of the 10 have "D" in them (all but 47)
1 more satellite is on/off/hollow bar (01)
location accuracy +/- 18 feet