On a tour, I took individual tools, and found that messing around with individual allen keys (which I needed to do more than I'd care to admit) wound up being more of a hassle than if I'd brought a multitool.

One problem with a lot of kitchen-sink multitools is that they put an allen key and a spanner on the same tool, so you can't use both at the same time, which could be a problem. The Park rescue tool (linked above) cleverly sidesteps this problem.