Last June I bought a Garmin Colorado. Like several other owners, I sometimes experienced drift when in woodland (on one occasion over 600ft). A GPS software upgrade (not a firmware upgrade) released around October or November appeared to sort the problem out and after that my Colorado seemed to be on a par with my 76CSx.
A couple of weeks ago I managed to damage my Colorado and sent it in for a replacement. Yesterday I got the replacement and it seems to be a brand new unit (serial number