Side autonomy ... it is up to 18h-19h, so this allows you already attacked the majority of large trails (not ultra XL has ..sauf recharge along the way).
I take a star unlike the Garmin 305 lt No recalculates the distance following the loss of the signal (especially in tunnels). Answer Garmin have to buy an accelerometer! Conclusion observed regression and 910XT also is not spared, we feel well the manufacturer aims to sell even more by removing this feature!