There was a thread on Delta, Acros, and TMX on PN the other day. The general consensus and my opinion as well (at least in comparison to TMX) is that Delta has the most latitude of the three. It's the most forgiving in terms of getting the contrast one wants without blowing highlights to heck. it's also easy to get there - it's very pan-developer friendly.
It's my 100 speed film of choice. Souped usually just in ID-11.
allan