Sadly, Paradox has a habit of railroading changes they like onto the players without giving them an option. CK2 would be an amazing game if the post-vanilla changes would be introduced as options, not as changes to the game. Toggle India, coalitions/infamy and shattered retreat off and the game is amazing again. Of course this is my opinion, maybe others feel differently, hence options rather than hardcoded changes would be an interesting approach.
I really like the idea of options. I bought the game shortly before The Republic" came out and I have noticed that my enjoyment has decreased exponentially. The game feels like an "early access" game with the amount of game play that has changed. The game itself is vastly different in play style now from when I picked it up.
I really liked version 2.0.4. After "Rajas of India", the game slowly got worse for me. The one poster that said above that he liked some ideas and hated others, this rings true from my experience with the expansions past 2.04. Retinues were so drastically changed, they are almost useless now. I enjoyed them the way they were. The introduction of vassal limit in the Charlemagne patch made me resort to editing them to high levels after every patch so I could "conquer the world" again. I understand that many people dislike conquering the world on this forum and find that unrealistic, but that was something I did enjoy that was taken away. The nerfing of features that we had previously, really nerfed the fun I had with this game. Fun > realism, anytime in my opinion.
I have not bought Conclave, despite having bought almost every other expansion (and tweaking out the things I did not like). I can say I HATE shattered retreat. I turned it off as it is not fun, besides being completely unrealistic. Despite turning it off, my armies "ping pong" between territories and can never effectively conquer units anymore. I wonder, Dev team, are you trying to kill your own game?
If the answer to the above question is "No," you may want to greatly consider adding options to turn on or off these major game changes. I am not a professional game designer, and this is only my opinion, but I think expansions should be adding features, not tweaking existing features to fit the expansion which turns the game into something that I did not pay for.