B-29_Bomber
Banned
Your game will be significantly slower as there is a lot more for the computer to calculate, but I've never been able to go back to the base game since playing it. More provinces, trade hubs, nations, events, plagues, etc. The only problem at the moment with it is that you have to be more careful in regards to the "Saving Bug" (so definitely no Ironman) as the threshold for that is a lot lower with more memory being required by the MOD; this means I often play twenty or thirty year stints before saving and restarting the game so as not to encounter it, though even then it can sometimes catch me unawares. They also haven't been updating it while working on their overhaul (MEIOU 2.0), which has caused some pathing issues for events; nothing game-breaking, but it does lead to weird quirks like leaders names not showing up in events or decisions.
Actually they have been updating it. They had released two or three major versions and a number of minor patches (they just released their fifth patch for 1.27/1.19.