I just did a quick look at the Garmin website. I suppose you have checked these units out in depth already, so, being somewhat lazy, let me ask a couple questions. Do the newer Garmin units make it easy to import/export maps, tracks, and waypoints directly to/from the units using wifi? Are there sources for maps from third parties that can be imported to the newer Garmins?
My old eTrex Vista C has to be connected up to a computer using a USB cable and the maps and dataset you want to put on it are loaded using the Garmin BaseCamp software which I suppose is now obsolete and replaced with something else. I have the Garmin MapSource software, but don't remember using it. There were several free base and overlay maps available from third parties. You could even make your own custom maps, although I never did that because it looked like a difficult process. I actually liked BaseCamp as a standalone map software for use on my laptop, but haven't used it in a long time because it is easier to use the app on my phone. I remember that one limitation was not being able to display more than one map at a time, so overlays wouldn't work, except there was a way to run a virtual Garmin GPS on the computer and it would trick BaseCamp into thinking there was a GPS attached and for some reason it would then allow multiple maps/layers to display.
I doubt I would be in the market for another standalone handheld GPS, even with built-in satellite communication/PLB capability. Like you said, they are expensive and I'm kind of cheap sometimes myself. I'm sure they have a bit better accuracy and that would be nice to get better waypoints. If I do anything, it will probably be to buy a standalone PLB.