Garmin 12 XL - still have many in use , take a lot of abuse have all the
features we need battery life pretty good.
E-TREX - we have been unlucky with these and do not recommend them
Garmin 72 - great low cost unit we like the fact that as an entry level unit
( about $130 ) we can use UTM or Lat/Long with one click - solves the
worries of teams needing both at a moments notice. Battery consumption - we
plan for changes every 8 hours for safety ( 2 X AA ).
We use ours for 2 main purposes;
a) We train the teams to use GPS as a check AFTER they plot where they
are on their maps
b) Tracking teams for "where did they really go" - normally the GPS
is on all day then we download each when they come back to see the bread
crumb trails.
Garmin 111 Plus - all ours have been excellent heavy duty, long lasting and
a good full day + on batteries ( 4 x AA ) I always carry one as a "back up"
and leave it on all day in my pommel bag - has come in handy when a "new"
toy didn't work ! Believe still on sale .