If you can swing the cash go Garmin. Im assuming your a Clyde as your posting in the forum. Being a Clyde myself, I use the Garmin 705 GPS/Heart/Cadence/etc and the unit was priceless in allowing me to complete the 200 mile STP ride last month. I was able to monitor my heart-rate for the full ride and keep my effort within a suitable HR for endurance. Before the Garmin I used a PlanetBike computer - another good computer but i have a tendency to try way too hard at the beginning of a ride and PlanetBike comp gave me no indication of this.

The Garmins also have web-based displays of all your ride details that are very cool to review:

http://connect.garmin.com/activity/41109107

HTH, magohn