I have a vista hcx and venture hc. The venture has limited memory and no electronic compass but was and is still useful. I like the electronic compass on my vista, mostly for the fact that I can show the gps to my hunting/hiking partner and the screen won't jump around.

You don't have to pay for maps, gpsdepot has free ones you can download and put on your gps. I even have the local maps on my venture, since it doesn't hold as much I can't put the whole SEusa map on it but I can put the hunt club and area I live.

Be aware that some of the information you get may not be correct, like the odometer. The slower you walk the more error there will be. It's not really a big deal as long as you are aware, some people get all bent out of shape though. A gps is just a tool with some limitations, just like any other tool. If you practice with it when you are hiking and walking, you will become familier with it, and it will be more useful to you when you need it.

I save my tracks and use a website called gpsvisualiser to project those tracks on satillite maps. I save and print them too. I save a "waypoint" whenever I find some kind of interesting feature, like tracks and bedding areas. Next year it will be even easier to put my stands in good spots! Plus it helps me stay out of the way of others.