I am a relatively new geocacher, but I studied it through and bought a Garmin Nuvi 350 to use in the car and for caching. I am 100% pleased with my decision. Most of our hunting will be done in the city, so the automotive stying and features of the 350 make it perfect for getting us to within a few hundred feet of the site.
Once we have arrived (after the nice lady from the little box tells us every turn to take), we just change the mode to "pedestrian" and the nav setting to "off-road" and we follow the icon to within 5 feet of the cache. we have searched for 10 caches and were able to find 9 of them. My 9 and 11 year old sons were able to use the unit straight out of the box with no assistance. They love holding it and letting the unit guide them to the hidden treasure.
We just plug it into the computer via USB and load the coordinates right from the geocaching.com site. It was simple to set up. When I get home from work, my kids will have the sites selected and we will load a few each night and then go out on the hunt over the weekends.
I know that there are more sophisticated units out there. My dad has a really fancy rig he uses for hunting and fishing. I need something that is easy for my whole family to use and something that can still help me with actually getting CLOSE to the cache site. The Nuvi 350 is perfect for it.
I will admit that I like the factory radio in my car, I still have an old 27" picture tube TV, and I don't have a MAC. But, this Nuvi adds some real cool factor to my world. Though it is simple to some, it is the most awesome thing I can imagine. Everyone has their perspective, I suppose.
I wish you the best on your caching and on your hunt for a GPS. I honestly believe I have discovered the world's best family sport. I cannot believe that all this fun has been hidden from us for years!