Storywise, I do like the guy, but even if you can side with him to destroy the Dark Brotherhood it is obvious that the DB is supposed to be the faction the Dragonbron joins, them being having more quests, story etc...
I have read the 2 TES novels and I kinda like the whole Penitus Oculatus faction, I hope that we may join them in a future TES game.
And what about the rest of the players, did you kill or not commander Maro?