went from OS Map, to Memory Map PC software and firstly old Garmin Etrex (*no map, direction arrow, compass, speed etc etc – now for sale) now on Satmap OS50,000(*bargain bundle a while ago).
Satmap is a luxury really but it does save hauling the map out on most occasions. ie if you’ve got a 5 way crossing then an arrow to the L doesn’t always help so you might have to go a little bit to get confirmation, with the rolling OS map you get extra ‘pictorial context’
You can help the no map GPS by planning the route/waypointing on the GPS accurately and I tended to put routes/waypoints slightly ‘before the turn’ so the arrow was pointing before you got to the turn so you were looking for a left in the near future sort of thing.
For routes/distances etc both GPS were fine(*Satmap is easier as you always have map confirmation ability on screen) but I always take map anyway as the ‘screen size’ allows diversion/emergency etc planning more easily.
In terms of planning I use highlighted paper OS 50 maps (quickly see loops/routes etc of the right size for me in an area I want to visit) and PC software as it ‘contours’ the ride with no effort atall.