To say I don't agree with smartphones almost sounds like an anti-religious rant in this day and age but I resist as I don't want to fall into the trap of having my nose in one when I should be socialising. So until it packs up, I have my ancient Nokia. It's is small, light, lasts ages on a charge and does everything I want a phone to do.
For planning walks, I use Memory Map, Bing (as I don't have 1:25000 for the whole country for Memory Map) and/or paper maps. It really depends whether I happen to be on the PC, iPad or not or on holiday. Either way, I love my paper maps and always take one on walks, plus compass.
For navigation in the field, I generally use my old Garmin Geko, with pre planned routes downloaded. It does not have maps but is perfectly adequate most of the time. Once you get detailed maps on these machines, the cost shoots up and I balk at paying! I am a Yorkshireman!
Occasionally, I need the map if, for example, I need to know which side of a field boundary the path runs, if not clear on the ground. Sometimes, especially across farmland, it is actually easier to use the map as you can keep track of where you are in relation to farm buildings, fields etc.
Currently debating with myself whether paper maps or the laminated variety are best. For some areas, I have both. Paper maps can be folded over in a map case for the bit you want but often have to be taken out and re-folded. A pain, especially if it rains or is windy. Laminated ones are too bulky to keep folded over in a map case, so you have to open the whole thing out each time, though more manageable in wind. Printing out and laminating. (Say from Bing) is not always practicable as you might need several sheets. Anyone got any views?