I have an HTC Incredible smartphone on which I use the Geocaching.com app. My GPS is a Garmin GPSmap 60CSx. While the Incredible is a fine phone, the GPS wins hands down when geocaching and a few other outdoor activities. Battery life is in favor of the Garmin, and yes, I do have the heavy duty battery. While geocaching, coverage in many areas is spotty with the cellphone.
Do both have great attributes? YES! Do both have room for improvement? ABSOLUTELY!! But when I'm caching the GPS is my #1 choice.
If you don't care for your Oregon 450, I'll be happy to take it off your hands!
Final comment; whatever you use, have FUN caching...