I don't like calling it "inferior" (and we didn't, at the time). We solved a much more general problem in a slow and only approximately correct way. They found

I don't like calling it "inferior" (and we didn't, at the time). We solved a much more general problem in a slow and only approximately correct way. They found a much more limited problem that they were able to solve perfectly and blazingly fast. That's a feature! There was definitely room for both approaches. The multi-height thing was a real annoyance, by the way. For example, my path-finding code really wanted to be 2D (and of course it was mostly expressed in 2D) but had to understand that you could do things like take a bridge over (or even jump over) a gully and then walk around and cross under your original path.