I tried the G1 with an RS800SD for a while. The performance is good. It receives a signal through most conditions, and is generally accurate. Comparable to a Garmin.
I sold it, though, for two reasons. The G1 sensor is big and ungainly. I thought from the InterWeb pictures that it was like the size of a Polar S3 sensor, but it’s really, really big and heavy. It might be OK as a permanent fixture on the bike, but I never found it comfortable to run with.
And it was very frustrating and time consuming to download the data to my computer. Both the IRdA and morse code download processes are unwieldy. Some people do fine, others struggle. I would consider waiting for Polar’s new RF-based download system if you’re going to go Polar.