....... I have been using an iPad as an EFB for several years now and I feel that it is a very adequate replacement for paper charts. It's not perfect, but it works well. Considering all of the other advantages of the iPad, I find it to be the best solution for carrying the required publications on the airplane.
Every time this thread comes up, I read a lot of comments how the glare is unacceptable, etc., yet the iPad as an EFB has become very successful, with many airlines, military, and general aviation pilots using the system. I read somewhere that the government paper charts sales are about half of what they once were and declining, the author acknowledging that the iPad was clearly the culprit.
Retina vision was a noticeable improvement, and I expect there will be future advancements in screen brightness. I'm not looking back, this is the future, in my opinion.