I still like a big paper map for planning, a laptop-sized monitor isn't too bad but I'd never then walk anywhere remote without a hard copy anyway. Though usually just as a backup, as I've really taken to using a mobile device when out and about - partly because of the GPS and partly because the zoom is helpful with my eyesight.
But fundamentally it is the OS mapping that I'm a fan of, whatever the media or technology behind it. I also do a lot of walking on infrequently used paths in relatively domesticated landscapes (i.e. with lots of boundaries), so appreciate the 1:25,000 scale in particular. And need it to work without an internet connection, since even within spitting distance of major towns and cities phone coverage can be pathetic, let alone out in the middle of nowhere.
So personally I'm thinking of moving to OS's own apps. Their electronic subscription is tempting for geographical flexibility, whilst the map+code purchasing system seems to offer the best of both hard/soft-copy worlds (without needing a decent printer). The relative cost could be hugely different though, depending on how many new maps would be needed each year and how many years one might need them for.