I've tried doing some navmeshing, but found that in exterior cells, the automatic generation (at least going by how the wiki says to do it) is just terrible, almost useless. Would the devs have had to do it manually? It's impressive if they did, I mean navmeshing is pretty tedious.

they probably had the autogen make a basis then they hand-tweeked it.

The tutorial steers people towards recast navmesh, but I've found Havok navmesh produces vastly superior results, especially with "overlap distance" set to 256.

Here. http://www.gamesas.com/topic/1345681-navmesh-bug/

Havok navmesh?

Let's keep this in one topic.