I'm really happy with my Lezyne Super GPS - it's not too large, has a highly visible screen and the battery life is fantastic (interior lithium battery USB rechargable). I actually the GPS mounted on the handlebar for speed, distance, time and heart rate display and use my iPhone with RWGPS and GaiaGPS carried in my jersey or a food bag for navigation and mapping and backup tracking.

If I was shopping for another I'd definitely get the Lezyne Mega XL GPS for even greater battery life, good mapping, and a larger display.

Howard