Re: Batteries not included
My tuppenth worth.
As a climber and mountaineer, I am quite amazed that you would see the paper-based map as a secondary or backup system. Don't get me wrong, I've had a love affair with maps and sea charts all my life and really like many of the advantages that GPS/Phones can provide. Companies like MemoryMap digitised OS maps back in the early noughties which where truly excellent, but sometimes were buggy or simply crashed/conflicted with other apps. Paper-based maps don't require batteries or crash.
Obviously, this is very dependent upon where you are - walking around Windermere or a simple trek in the countryside, then all good, but anyone that regularly spends time doing this sort of thing, would be used to using a mapcase. You simply fold the map so that your proposed route is presented through the waterproof cover. Additionally, the laminated OS maps are simply excellent and well worth the investment.
Being reliant on GPS or a phone is not a good thing. Your GPS/Phone should be seen as your backup. I carry a dedicated GPS with OS 1:50000 maps of UK and have SD cards with various European maps as well. In addition, I have quite a few mapping applications on my phone.
Only saying :)