I bought the Edge Explore while on a bike tour from Belgium to Italy. It gave me more headaches than guidance. Here's a list, ordered from serious ballache to requires improvement. Note, this was all done with the preinstalled 4.20 software, but since the release notes I found do not mention these bugs, here I go anyway:
1. Device becomes unresponsive during rides
Usually somewhere around the 80km point, the device has refused to wake up by touching it, or pressing any of the buttons. Three things may the happen:
a) very rarely the screen comes back on after a few minutes
b) very rarely the device automatically restarts after a few minutes
c) most of the time, I have to press and hold the power button for a while to manually restart the device.
I don't have to explain how annoying this is while navigating a city (or any other course). Most annoyingly, there's no way of telling that it has become unresponsive until you try to look. So you might just be going forward and off course for minutes before you realise the device isn't responding.
2. Incident Detection totally haywire.
Within minutes of activating Incident Detection, my friend (thank God I didn't yet put my parent's details) started receiving occasional messages. This also happens during rides. He says he received about 6 emergency reports on a 100k ride. My phone did not sound a single time (probably because it's always on silent).
It's not clear when incident detection is triggered, but it's clear that it's much too sensitive. Not a single time did I fall off or abruptly stop my bicycle. The incidents also went off while the unit was charging in the hotel room.
3. Auto-sleep has issues
a) it sometimes does not go to sleep when the lap banner has come up while going to sleep, and after tapping it away, it sometimes refuses to go to sleep ever again until the device is restarted
b) sometimes it refuses to come back on after sleeping (see #1)
c) when the device wakes from sleep to give you the next navigation guidance, it sometimes shows a stale image (of a turn taken a while ago). This seems to happen particularly when the device went to sleep on a screen other than the map (e.g. the data screen). This has sent me going the wrong way more than once.
d) when the device wakes from sleep for the next navigation guidance, the track isn't always north as requested in the settings.
4. Routing doesn't favour continuity
Taking me across a bridge across a river for a mere 1 km of "bike path", or often just gravel, and then dropping me back on the original route, is pointless. It slows me down as I now have to navigate, take turns, and it's not like 1 km makes a huge difference. Continuity should definitely be favoured for stretches under 2 km.
5. Custom routes with the same name get overwritten on the device
And the software does not help by assigning silly generic names such as "Riding 20 July" to each new route
6. Loading your own GPX is complicated and doesn't work with every GPX file.
It should be as easy as picking a GPX file from your phone's internal storage through Garmin Connect. But instead, I have to open it in Files (Android) or Total Commander, and then tell it to open the GPX file with Garmin Connect.
7. Poor recalculation of route on custom GPX
If you use a custom GPX and you decide to freestyle a bit (e.g. take a shortcut, or take a bike path that's not on the map), the Explore stubbornly tells you to navigate back to where you last left the course, rather than trying to join you up with the nearest point of the remaining course. Could be a bunch smarter.
8. Battery indication inaccurate
While navigating, the battery indication may say there's 40% left. After restarting the device (because of issues such as #1), the battery indicator now says 60% again. Sometimes, the battery indicator also does not update.
9. No overview of the entire elevation graph when a route has been started.
Would be nice to see where you are on the entire elevation profile, rather than in the next 2km or so.
10. GPS Mode toggle stuck after not finding sattellites
If the unit cannot find satellites and you tell it to stop searching, it has a cross through the GPS widget in the drawer. However, tap that and the "GPS mode" toggle will still be on. You then have to untoggle and retoggle to turn it back on. Something tells me that there's poor state management in the firmware.
11. Search is ridiculously slow.
It should not take minutes to find a few cities in the menu. Something tells me that city search is not using the most basic search optimisation from the book (buckets) but rather trawls through its entire database of city names before displaying results. That's ridiculous. If you have buckets, you only have to search the B-R bucket if I type Brussels. Also, exact matches should be at the top. For example if you search "Milan", the actual entry for "Milan" is so far down the list it doesn't even display on the screen until you scroll.