i’ve been using one for a few weeks now, it seems to work aswell/better than most phones (my ‘plots’ are as well defined/better than my friends who use their smartphones)
you have to be careful with the button – there is only one – it’s very easy to press, you could easily turn it off in the middle of a ride/run.
there is no battery life indicator, but it hasn’t been a problem yet…
(i think 20hours is claimed)
it’s a bit of a fiddle to get the gpx file; you have to open the unit-specific software, connect the box, create a new activity, right-click on the new icon which has appeared in your activity callendar, export to gpx (save it on your desktop or wherever), open strava, and upload the file.
not a total nightmare, but less convenient than simply pressing ‘start ride’ and ‘finish ride’
it’s a bargain at £20.