Like any product there will always be tredeoffs. A solar charger small enough to backpack/camping will not be a very good charger for long term and a good long term charger will be too big for camping/backpacking.

I've standardized on the new low self discharge NiMH batteries and carry two sets for each electronic device I have and then a few spares. With theose I can run 2-3 days without needing to re-charge anything and I can carry a lot of spare batteries in the space a solar charger would take up. So my plan is for bugging out on foot I'll run off the batteries I carry and my small good quality charger is for when I arrive at my bug out destination and I carry its 12v and 120v cords. So any camping trips I just make sure all my batteries are charged brfore leaving. My GPS can run 12 hours on a set and I have the dedicated spare for it, our digicam 500 pictures on a charged set, etc. So most gear can go plenty without needing a re-charge.

When I add on a solar panel it will be in my longer term gear and not my short term bob and will integrate with the rest of my gear, i.e. I plan on a 12v out panel so I can simply use all the existing vehicle adapters for my gear rather than having a dedicated solar battery charger. So my gear system is more modular and flexible. Eventually I plan on a small panel at my bug out location, one on the truck and one at the house and any of those can be taken to the bg out location if needed.