Just IMHO
I have had a few over the years but have stuck with the Garmin 500 (which is mainly a Bike computer). Garmin offer a newer 510 version but still offer the 500 because cyclists like the unit more then the newer one.
Also I have a garmin strap that can hold the 500 when runnning so I train and race with the single unit for both Bike and run. (will be using it in Roth). The 510 is probably a bit big for running with.
The 500 is probably the cheapest of the fully functional bike GPS computers and is being discounted now that the 510 is here.
Rgds P