6-8 hours of caching? how do you manage that?? I have the same phone and its battery life is fine for general use, but the second I start caching with it it drains very quickly indeed - I put it down to having the screen constantly on and the GPS on.
Hence I very rarely use it for geocaching, only if I’m somewhere unexpected or don’t have my GPSr on me.
When I have used it though, yes, it works just fine in terms of ease of use and accuracy. From what I understand the GPS on there is better than the one on the old iphones (3, 3GS), and on a par with the new ones (4)
I've also got the same phone. With the GPS turned on and using one of the geocaching apps I can almost see the battery drain before my very eyes. I'd be really interested to know how you get 6 - 8 hours life out of it. It's a very good phone, but I wouldn't use it for caching or navigating unless I didn't have my Oregon.