So I find out yesterday that Garmin units calculate speed via GPS (no wheel sensors needed). Didn't know that before, that's logical.

I was hoping the Fred Brain Trust here could answer a few questions about Garmin units:

• Will they recognize my Cycleops HR strap?

• I presume they will recognize the Ant+ Powertap hub: will that include the cadence and speed calculations? Does the Garmin speed calculation over-ride the Ptap hub speed data?

• Will the Saris Power Agent software on the Mac recognize the Edge units and download similar data?

• If Garmin units calculate speed via GPS, then why do they sell a separate cadence/speed sensor? Is that just for speed?

If I get a Garmin it would probably be the cheaper 500, I could give a fark about GPS maps. Pcad knows where the eff he's going when he's on a friggin bicycle for crissake.