Interesting question. I've really downgraded my GPS in recent years. With high quality satellite imagery, and the ability to overlay many different maps I use a tablet for scouting and a PC for planning. I've found no substitute for paper so I'll print out pertinent maps which are great for outlining plans with the hunting party. Generally everyone gets a printed map.
I never met a handheld GPS that I really got along with. Low level (and often illogical) operating systems, subpar GPU's, proprietary formats... While actually hunting, I carry the smallest, simplest device I can - I mark waypoints like 'truck' 'camp' 'kill' in my GPS, but that's all I use the handheld GPS for - waypoints. All mapping is analog, or pc/tablet.
I'm sure there are some pretty capable units out there - look forward to hearing what other guys are using. I've just found GPS to be most valuable when maps are not (dark/weather), and maps to be the most valuable when I can manipulate them and draw on them. Because no product has been able to integrate these two concepts to my satisfaction, I've found separating them to be a natural solution!
For context, I have done a fair amount of GIS/lidarr for work. I have access to proprietary oil/gas and forestry maps. I'm not a Luddite!
External GPS was one of the first accessories developed for the iPad in 2010 when pilots discovered how useful an iPad with real time positional information could be. There is a LOT to be said for using a tablet as a GPS.
Then again, it just doesn't feel like hunting with an iPad... does it? Or is this what being old feels like?