Garmin 120 here! Huntin partner has one too.
(Ford Powerstroke Diesel!)
Feature wise, The Garmin Rino 120 is middle of the road. But anything less, then I'd be putting it up for sale soon after hunting season. The 130 is nicer with it's uploadable maps. The included radio doesn't provide as good a reception or broadcast as a separate handheld Cobra GMRS, but it's nice to have the radio with the new feature of sending location to other 120's on GMRS instead of the limited FRS frequencies. When the GPS is on, I turn the radio off as that's the biggest power drain. I leave the GPS off most of the time to save battery life. When we're separated, we turn the GPS's on at the top of the hour. Otherwise occasionally to set waypoints. I like that the power button is hard to get to, so it doesn't turn on or off in the day pack. I wish my GMRS radio was like that. The Garmin is rugged and has a convenient belt clip like many cell phones. I still stoss it in the day pack in a protective padded bag to save the view screen.
As for having a radio when hunting, well, for safey sake, I don't think there's a game warden out there that'll write a citation for having it on, or on you/off. If you're busted communicating a game drive using electronics, which is illegal in most areas, then you deserve the ticket. (game drives of any sort are illegal in Wa.) Fisherman have used electronic location devices for years to mark fishing spots. The handheld GPS is just the tool for the hunter that likes to get off the the beaten path. A teriffic tool to help you find your way back to camp after dark when you can't see the land marks.
Learn how to use it before you go hunting though. Define your specific need, and still carry a compass and map. We learned the hard way that fidling with the GPS on a hunt is not the best way to spend time hunting. And we learned that very heavy cloud cover or dense fog can impede the satelite signal. I still carry a lensatic compass. Not that I don't trust the 'lectronics'... But I don't leave things to chance.
For conveinence, unless you see a used one somewhere, Ebay isn't the best deal on these. For new units, We found that Walmart on-line had the best price shipped to the door.
-Steve