One very nice "hidden" 1K benefit I experienced in the past (a number of times at both DEN and ORD, and once at IAD, probably about 15 times total) was that United put me up free in a hotel overnight, plus provided a meal voucher, when I was delayed and missed the last available flight out. I received a free room even for weather delays.

However, it has been several years since the last time I received a free room, so can someone confirm that United is still doing this for 1Ks?