Draw distance issues?

A friend was showing me her new build today: it involved a house down on the land (at about 40m) and an elevator shaft leading up to a skybox at about 250m.

Using the elevator shaft as an anchor I cammed up to the skybox from the ground, but it wasn't until she mentioned that it was located at 250m up that I realized I shouldn't have been able to see it because my draw distance is set to 96m. Everything is unlinked and I was always on the ground, so it wasn't an issue of "rezzed because I've seen it just before" that happens sometimes.

I always assumed that draw distance would work in a sphere with the specified radius, or is it really just a cylinder with infinite height?

I don't know, but my wager is sphere around the camera.

I haven't noticed anything different about draw distance. As someone who regularly cams up to a 500m skybox from the ground, I would think I'd notice something like that. However I do know they changed something about camera constraints. I always disable my contstraints from the debug menu, and it used to be you could zoom in very closely to prim items just by normal Ctrl-Alt camera movement. However that no longer works. It makes working on tiny prim builds more awkward, as I have to use Ctrl-0 and Ctrl-8 now, which isn't as intuitive. So if they changed that, who knows what else they may have changed.