As of this posting I'm just under 500 finds and have been using a HTC Hero or HTC Evo 4g on most of them. My dad uses an Oregon 450 so we compare our results alot when out caching and while the Oregon is more accurate, these HTC devices are not far off. It helps to use the app "GPS Status". Open the app> hit the menu button> select tools> select Manage A-GPS state> then select download. Doing this every few days seems to really help the accuracy. In my opinion the main reason to go with a dedicated gps would simply be that they can take more abuse. My phones been dropped, rained on, and covered in pine sap already. I told myself that once I get to 500 caches I could buy an Oregon, so I'm starting to shop around now.