One of the readers of this blog commented on my previous post and found another support article on Polar site about the RS800cx sensors. Besides the well known information about the types of sensors that are supported this article also provides interesting details about the simultanous GPS use with the S3 and CS speed sensors. Direct quote is:
"If you use Polar RS800CX to measure data from the G3 sensor and either the s3 or the CS sensor, the G3 GPS sensor is used for location and route tracking while the other sensor is used for speed and distance and other measuring. If the s3 or CS sensor should ever be out of range (for instance if the type of sport changes during training), the Training Computer will automatically start collecting speed and distance data from the G3 GPS sensor. This secures speed and distance measurement throughout your training session.
Polar fan club rejoice the new watch will have it all. Now only if it also supported calibration of the sensors via G3 that would be cool. But I'll take just this as well. I'm already looking forward to next week when the watch should be available at least in some European markets (Germany was confirmed by Polar rep few weeks ago).
ds50 thanks for the comment and link.