To RCX3 in:
The RCX3 in itself has only a few basic functions for training. In order to use the full functionality of the clock, the free usable website [...] is necessary. Also functions as custom workouts, time or distance based interval workouts, etc. can be used using this website. The range of functions can be here in my opinion, nothing to be desired, especially because (now) are also interval workouts defined and transferred to the clock.
For a cycling computer RCX3 has few functions, in particular lack the fundamental functions of a cycling computer, such as an odometer. Such can also be realized only through the detour of polarpersonaltrainer.com. Definitely not an elegant solution.
GPS function:
The included GPS module G5 has proven to be very accurate and can relatively quickly (normally within 1-3 minutes) to establish a GPS connection. In polarpersonaltrainer.com the route afterwards on a map can track; since an update of the web platform now also elevation data are available.
It should be noted that one in RCX3 - can not set the "sampling" - as opposed to RCX5. The position of the clock (or the GPS sensor) is only once every five (!) Seconds updated and recorded. For the mass Running this will probably be sufficient in cycling thereby suffers both the accuracy of the recorded track and the precision of the currently displayed speed noticeably.
Conclusion:
For me, the RCX3 with GPS sensor is thanks to the functions of polarpersonaltrainer.com simply the perfect Running Watch and fulfilled for me all claims that I have, (as an amateur runner) to my heart rate monitor including training programs and interval training (via web platform).
As cycling computer clock is suitable (without bike speedometer) in my opinion due to the unchangeable, slow GPS sampling only partially, particularly if you put on a reasonably accurate speedometer and a precise map display the route value. For an accurate speed display is the acquisition of the corresponding sensor - at least in conjunction with the RCX3 - unfortunately inevitable.