I never waited, except for waiting for the next car (with one caveat, see below). Or a few times I waited because I wanted to sit in a specific place (front car, usually).
Okay, my caveat... I think a "touring plan" is important. I avoided 7DMT until the middle of the night. I started with adventure land and very, very few people were there. BTMRR was running with trains half full, at most. After adventure land, I skipped fantasy land again and went to tomorrow land (empty space mountain). I think a lot of people started with fantasyland and that's a mistake, IMO. For two reasons... one because that is where most people went at the same time and two because the regular park queue needs to finish before you truly get walk on. I went to fantasyland after Tomorrowland and by then, the crowds were gone to the other areas. I'm planning on a similar approach for January.
I rode just about everything once, except I rode space mountain, BTMRR, and 7DMT over and over (well over 5x each).
I do think (as
@GADisneyDad14 posted above) it's quite possible that 2018 is more crowded. They are advertising it better. And the reviews from last year were nearly 100% positive. There might even be people as crazy as I am, who made a trip specifically for DAH (as opposed to last year when it just happened to work out for me).