A digital back is simply a different method of capturing the image data, i.e a substitute for a film back, generally speaking the larger the film/digital back ( assuming exposure etc is correct ) the better quality image you will have to work with in the darkroom/computer. The important factor is to save all the image data in a big fat raw file or whatever format is used in these backs to save uncompressed image data. The view camera movements and their resultant effect on the image will be the same whatever medium is used for image capture, having used view cameras in the past I can confirm that you do take extra time in composing and setting up the shot, the cameras with the necessary dark slides, extra lens, tripod etc. were a bulky item so every shot had to count, no blasting 30 or 40 shots off of the subject to get one right, using negative film the rule of thumb was to calculate the exposure, shoot and take another shot with the exposure doubled as an insurance. When discussing Mr Adams work something that is often overlooked is that his work was based around a combination of exposure calculation and corresponding negative processing adjustment.