I love having a tripod at the parks. On our last WDW trip, we were there 10 days, and every day I either had my monopod or my tripod. At this point, I probably wouldn't bother with the monopod.
We have an advantage in that we brought our own stroller, which has room underneath for the tripod to hide away during the day. At night, there is simply no substitute for having a real tripod IMHO. Now, if I had to stash it in a locker, I might be less inclined to have it with me all the time. But I'd still want it at least 1-2 nights at each park.
Usually my MO was, once it got dark enough to do tripod shots, and I was in full shutterbug mode, I'd leave the legs extended and the remote shutter release attached to the camera. When I found a good spot, I'd spread the tripod legs, pop the camera onto the quick-release, aim the ballhead, and click away. When done, pop the quick-release and move on. It really was a fairly quick operation.