Previously I had a Polar RS200. However, I have not used the last Fußsender because it was too cumbersome to me this always switch between my different shoes. Therefore, I had about a year ago found my running data with runtastic. Here, however, the GPS has me my Sony Xperia V often times left in the lurch, also suddenly became the H7 chest no longer recognized by a Runtastic update, so that the pulse measurement had to play again the old Polar. This now comes to an end. GPS Tracking: So far, the GPS has been recognized more and more accurate than the phone. That made for an 11 km run from even almost 600 meters. The mobile GPS made with winding roads often times abbreviations by the botany while the M400 has always "followed" the way. Search The problems with the satellite what other users have not yet occurred to me. But I stretch myself before running over and holding described during which the clock as described in the manual calmly. Polar Flow: The update available since 31.12.14 and 1.1.2015 now finally works also include meeting the workout data on the flow cell phone app. This extends the battery life of the M400 much that will survive about 300 charge cycles, should be recorded to greater performance. If you have to connect the M400 every cable and thus reload when its run data equal will check on the computer, then 300 charges are suddenly no longer much. 24 hours Activity measurement: This was keien purchase criterion for me, imagine now but amazed to find that I already am trying to get the full bar. Actually, I just wanted to put on the clock for sports, you have now but also from time to time so during the day at. Here the very rigid bracelet is incidentally my only minor complaint on the clock. Here a bracelet with a little more comfort would have been nicer. Conclusion: Clear, the V800 then some, for me as a "Abspeck" runners reaches the M400 but all times and offers everything I need. The additional cost V800 did not I think value.