After a great deal of research I have come to the conclusion that Dom2 is the King of turn-based MP strategy games.
What prompted the research was that a friend of mine was playing dom2 with me for a while now, but eventually gave up cause it was too complicated for him. So, we both spent the past week or so, scouring the net and various gaming archives, desperately searching for a replacement. And the result? There are none!
Perhaps the single most defining feature that made dom2 stand out was its Turn-Style. As I am sure we all know, Dom2 employs an Offline-Simultaneous turn method. This method allows you to play a game at a reasonable pace, scaling all the way from 2 to 16 players without any problems whatsoever. Most of the other defining features of dom2 as an MP TBS game (high game completion rate, smoothness of handling dropout players, less prone to connection probs) all came as a result of the turn-style choice.
For reasons I can't fathom, almost all the games out thier offer either
online/synchronized Simultaneous turns or some form of Serial turns. Both of which are just horrendous! Online-Simultaneous: because you have to have everyone online at the same time and just pray they dont drop in mid game. Serial turns: because it doesn't scale AT ALL with the number of players in the game and will consequently take you forever to play a game.
Additional bonuses of dom2 over other games were 1) The distinct lack of cheating in MP dom2 and 2) The tolerable level of micromanagement as the game progressed. These I simply attribute to the skill of the programmers.

Has anyone out there found a game that can rival dom2 in terms of Turn-based Strategy multiplayer play?