GPS fixed itself!
looks like this forum is dying.. so here is some good GPS news -
a few months ago, my GPS suddenly started working reliably, locking on within a few minutes to at least 6 or 7 satellites and estimated accuracy around 20-25 ft once it settles down. Still wanders off a bit in city blocks with tall buildings, but generally does the job.
No idea what fixed it, no changes in settings. I'd already tried the Samsung GPS fix, but it would still hang on occasion and need a reboot. Now it always works.