I wish I could speak more to the long distance hiking, but unfortunately, I haven't been able to do that yet. What I can speak to is the electronics and how they add weight. I've noticed a trend for folks to carry more and more weight in electronics (phones, cameras, tablets, mp3 players, e-readers, rescue devices, battery backups, solar panels - the list goes on). When I go out for 2-3 days, I only carry a cell phone - no separate camera, charger, battery backup, nothing. I put my phone in battery saver mode and, as I've so far hiked in areas with little to no signal, airplane mode. I carry a paper map and compass, and I try to minimize my use of the phone, the only exception being to take photos. Used that way, the one lightweight device holds a charge for the entire 2-3 day trip. Now, as you'll be out for 20 days, you'll have to add at least a charger, but if you use this technique, I think you'll be very pleased with the freedom and the weight savings, and after a few days you most likely won't even miss all that junk.

Now the one nuance I would add to this, which I sorta glossed over, is if you are doing a higher risk trip or you're just not comfortable going without it, then by all means bring a rescue device. I think that's totally reasonable.