Belt and suspenders. I always print (folding the paper, not cutting). Since merger, I have seen two instances of scanners not working (BWI and IAH) and those with electronic BPs were sent away to customer service counters for hard copies by GA.
The last instance was about 18 months ago so no recent experiences; but I don't consider it a hassle. I always connect and for the front end, I print BP at work to get back-to-back on one piece of paper.
When I board, I use either format.