I really like the ones that have very little memory built into them, but use microsd cards as the memory source for maps.

This makes it easier to manage larger amount of data (maps, waypoints, etc...) on your desktop, and incorporate only the specific information you need for the day/week/whatever into the microsd card. Then you can have multiple microSD cards; each up to 2gb I think; which means you can organize your information based on location and type of terrain (land maps, water maps, etc...) without worrying about any physical memory limitations.

While hunting, you can do everything you do with a gps with build in memory, but then the upload process is easier on the back end into the computer.

Other than that, make sure the casing is solid. If you're going to buy a new one, I'd say spend the extra money and get a bigger screen and color. It probably doesn't make that much of a difference, but it is a bit nicer.

I'm not sure how the radio incorporated into the gps has come along as far as transmission quality; but the theory behind it is great; especially if you have multiple people in your party with the same unit. You can transmit your position to your buddy via the radio.

I totally agree with Sproul on Garmin. I don't think I would entertain another company.

Good luck.