yep. been using powergrips for 17 years now, won't ride without them! perfect compromise between flats/clipless. they work on everything for me...
Brand new never used: $30. I'm in Oceanside.
Evan, I'm sure you have goggled each trail on its own thus probably duplicate info here. here are motos riding Tinta (looks fun from vid, but...
there is a real low key bike festival there called bloomfest. just show up and do some of their rides. You will be riding tons of good trails out...