I liked part two of the Abbott crossover. There were some great moments in it (the 9/11 conspiracy theories, Janine calling Dee a c*nt, the gang complaining about how Fall Out Boy always rips them off). My only problem is that up until the last scene, it's filmed like an Abbott episode and not a Sunny episode. I guess that was intentional, but I wonder what it would have been like if the entire episode was shot like Sunny.
Episode two was fantastic. The fact that they can put out an episode like that after twenty years is crazy to me. Frank literally created this insane plan for no reason other than to teach the gang how amazing cake technology is.
I haven't seen the other two, so I can't comment on them.