Until very recently I used this and very much liked it - combined a nice and simple on bike unit (no cables!) and nice review of your ride and workout. You need the sporttracks software though, as the stuff that comes with the garmin is junk (sporttracks is free, btw).
However, I have unfortunately had to move away from it as the heart rate strap is way too temperamental and after continuous failures (3 straps from garmin) it is not worth the time. Nothing is more frustrating then having a hard, HR based training plan on the schedule, do your warmup, and then find the the unit decided not to work that day. . .