As a Star Trek collector, I want the physical book to hold, admire, display, organize, but I've probably overfilled my dedicated Star Trek shrine/room since 1980 and - especially the recent IDW comics - the more recent purchases are stacking up in piles in other rooms. It's out of control.
I am currently on the second of two extensive overseas trips and took about four ST novels on each one, but was very pleased to have a digital alternative (a non ST biography in eBook on my iPhone) for those times when physical books were impossible to use. Nighttime flight, when you wake up and it feels selfish to turn on the reading light and shuffle around for the next book, I know I really shoulda brought some digital ST novels, too (instead), but iPhones do
run out of charge and not every airport has handy recharging facilities.
My eyesight is undergoing changes and I've had some eyestrain and watering, so an iPad with adjustable font will be an essential purchase eventually, but I still want my tangible ST collectibles in my hand.