We have used both the Explorer and SE models. Although the Explorer does not replace a handheld GPS receiver by a long stretch, I find that its added functions are worth the price especially the ability to set and load waypoints and tracks, and to see them on the device relative to current position. It can be used for simple navigation and trip planning. The phone app provides excellent topo maps with current location and a much nicer screen, but there's the inconvenience of pairing and having two devices running down their batteries.
Actual use in the field is a mixed bag. A computer is needed for setup, updating and loading data which can be a problem if away from good Wi-Fi or cellular coverage. The subscription model is convoluted and can add up quickly if the confusing settings are wrong. The screen, buttons and audio alerts suck. Communications can be slow or nonexistent (it uses a different and weaker satellite system than GPS). The receiver, phone app and computer website are inconsistent and do not always work in harmony. But, hey, it's technology so we don't expect it to be perfect.
