Ok, the thing he was saying about a Shapshifter with -13 AC is, IMO, referring to the Greater Elemental transformation.. I know.. I just played my Shapeshifter a few seconds ago. Anyway, I managed to get it to be .. er.. -14 AC with a Ring +2.
But in human form, I was.. er.. -9 (I think). I have the Bracers of Dex, and Black Dragon scales.
But if Greater WW, I think it's something like... -5 AC or something. But my thaco was always a poor 4-5.

But I mean, attacking a person 3 times kinda pays off.. hehe
And IMO, Druids are good mid-game, really. Coz at Level 17 (I think), I had 6 level 7 spells.. imagine.. 6 Implosions.. yay. While my Anomen (also at level 17) had.. 2.