I saw the woot, but decided not to bite. Didn't even look at the reviews but from some of the chatter on the woot forum I decided to pass. Here is some of my thought processes from looking...
It looked like it was a recharghable battery.
If it's a pack can it be replaced with regular AA's when it dies and your're still lost?
The downloadable maps are only very small quadrants, and only 4 are free...
XM radio... hmmm... battery killer! If i want tunes on the water I'll take an ipod.
Weather reports. Ok, now we're talking... this is handy
Electronic compass, is a big plus. You can stand in one place and recalculates North as you spin (like a real compass). You dont realize how nice this is until you have a unit that requires you to walk about 10 feet before it "sees" you are moving and recalculates north for you... ie no sitting in one spot and finding where north is.
I tend to look at weather reports and topo maps of the area i'm going into before I go, but things are constantly changing, so the last two points might be useful. If it were me, I'd pass... (besides I have an old garmin that gets the job done from 2001!)