I used to use a Zire 72 until the power connector came loose, now I use an E2 and a Holux 235 bluetooth gps, they work pretty well, but it takes a couple seconds for updates. Its handy to have the cache info and the gps in one unit, though losing it, scares me, or breaking it. I use GSAK and Cachemate to get caches in my E2 and track them, respectively.
Good luck, happy caching!