So does your device do what I am looking for - breadcrumb trail to follow, 3-4 data fields Ant+ and recharge on the go?
My eTrex 30 (which seems to be the point where Garmin got the hardware right, before losing the plot in later models) has served me well, but fails on your requirement for a power meter (it speaks Ant+, but only understands HRM, temperature sensors and the cadence half of combined speed/cadence sensors).
Breadcrumbs, 4 fields on the map screen (5 if you've got auto-routing turn directions), no problem.
I've only ever experienced crashes when auto-routing gets confused by some map quirk, or when the MicroSD card has come loose because the flap wasn't properly shut. The latter is bad design, as it's easy to dislodge it when changing batteries.
The Etrex 20 is effectively the same isn't it apart from the "built in" compass and altimeter.
I agree with your general drift though.
I bought an Etrex 20 and have recently acquired secondhand another 20 and a 20x as I expected Garmin to discontinue them. I also plan to take a spare on long tours.
I too get occasional crashes but it's no great problem to just reboot it and I can live with it. I had the impression that ONE cause can be momentary loss of satellites but may be wrong.
Was surprised to see that Garmin have just released new versions of the 20/x and 30/x but can't see any great advantage to them.
For general purpose use, despite some minor issues, I would unreservedly recommend the 20/30 series.
On the card flap I secure the top with that old cycling standby - a small bit of duct tape. Be careful that you just secure the top though - if you let the tape go lower it is possibly to pull the little flap/door of its hinges.