I use a handheld GPS for geocaching.
Magellans were about the equal of Garmins, but I have heard they stink now. The car ones (Nuvi, etc) are not that good for hiking and geocaching, but are fine for car navigation. Garmin is pretty good with fixing them. I have heard of people sending them in over a year after the warranty had expired and getting a refurbished unit in return.
The handheld ones are sturdy. I have a a 6.5 year old Venture. The printing on it worn off and some of the rubber is worn off. Last week I dropped it on a stump and cracked the screen, but it still works.