After seeing the Lion previews, I thought the 2d spaces would be a problem for me as well. However I was pleasantly surprised when I found that my keyboard shortcuts still worked (I use Cmd+# to switch to a space). Since this takes me directly to a space the animations is no worse than that in Snow Leopard.
EDIT: Hmm, that shows all of the defaults that are currently in the system, but I guess doesn't show you what extra settings you could set. E.g. that setting in the grandparent doesn't show up in my defaults.
