hi, you have a point there about it being a hassle while moving it around while lying down. I do move it back and forth between my side table and onto the bed numerous times a night. Also now i am imagining that the wrist placement will be worse on the 15"(as it is wider) to use while lying down. on the 13" mbp, as im typing, my wrist goes to the sides near the corners, and bending down till the elbow meets the bed. and its kind of sharp on the wrist. This is a different position as opposed to someone who is sitting down on a chair with the laptop on a table.
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Yep, I don't need the power for sure. I just thought that the retina display will make reading more comfortable and less straining. I get bad, temporary astigmatism whenever I read on the laptop intensively.