As a contributor to the Devnull mod, I think I can safely tell you that it really is no contest. If what you are looking for is the best long term game against the AI, TDM is the only way to go. Not only is it better than the Devnull mod in that regard, it's better than any mod out there. There really isn't another mod in it's class.
While Rollo has done an amazing job tuning the AI to work for the spceial techs available in the Devnull mod, and his Monsters are way cool
(And no slouches either), I don't hink I am off when I say the intention of the Devnull mod isn't to primarily make the AI harder to beat. That is however the expeesed goal of the TDM mod, and it accomplishes it quite well.
Geoschmo