Garmin Edge Tracklog and Mapsource Questions

I've gone over the manual for the Garmin Edge 205, 305 bike computer GPS.
Two things have caught my interest, 1) the unit has the new SiRF chip and 2)
the unit can log up to 3.5 hours of trackpoints logged every second which
comes out to 12,500 total trackpoints. The disappointing thing is you can
only choose between logging every second or using Smart Recording. No
option for user selectable time or distance recording. The manual also
mentions waypoints but does not specify how many waypoints the unit can
store. There is no mention of saved tracklogs but instead the unit can use
saved courses, are save tracklogs and courses essentially the same thing?
How many courses can the unit have at any one time? The Edge comes with
Garmin Training Center Software, will the software save files in a format
that Mapsource can read (Mapsource format or GPX) or can Mapsource download
directly from the Edge?

My main interest in the unit will be mapping Mountain Bike Trails. I do not
need to download maps into the unit. The Edge would replace my current
Garmin Geko 201. The Geko has worked great but the main (only) problem is
that occasionally it will lose lock under tree cover. Hopefully the Edge
with the SiRF chip will maintain lock better under tree cover.

Pete Rissler