I'd personally skip Citizen Stack as I feel Takara's MP Ultra Magnus was a better figure. With the rumours of an MP Megatron 2.0, you might do well to just wait it out. Even if you still prefer the 3P offerings, I'd think prices will likely drop further down the road. I personally still find Apollyon to be the most visually appealing between the three. Mightron seems to have a fun transformation while Despotron seems to really tuck away all the kibble cleanly. However, there's something about Despotron's aesthetics that just doesn't quite do it for me.