There isn't a "both" option... darn.
I love digital, quick and easy, I don't have to worry about damaging, fading, sweat stains. But I've gone through too many hard drives, CD's, and reboots that anything on my pc, at this point, feels only temporary.
I love manga for the feel of having the manga in my hand and the comfort of knowing they'll always be there when I wake up. Being able to read them thinking "I'm not focusing my eyes on a source of light slowly destroying my eyes", and the satisfaction of being able to scrap up the money to support the artist. But physical copys are hard to take care of, so far twice in the last 5-6 years of my collection's history, my little brother has spilled drinks on them twice, my (younger) cousin borrowed some losing 2 and tore up a third (missing pages...) that can not be repaired/replaced as easily as a digital copy can be. As well, I wouldn't be able to hide physical copies of hentai doujinshis in this room, only on this pc.
Both have there huge up's and down's for me that I can't pick either.