I originally purchased a silver mini 5, which comes with the white border. two considerations made me return it for a space grey with black borders: (1) Answering the OPs original question about reading in particular, I have gravitated to reading ebooks on a black background with light text and the mini 5 with black borders makes this reading experience better for me. (2) My iPhone XS and iPad Pro 12.9, being the new designs, have black borders and I wanted all of my devices to match as much as possible.