Do you find the 5dMkII Canon built-in flash control to be intuitive?

I find myself struggling to really feel like I've got a handle on it. I feel like I'm fighting with it rather than working with it. I often just run over to my speedlight rather than try to remember which thumb button to push to make the adjustments i need.

While I feel like I could use the camera's other functions blindfolded, I just don't have a natural knack for the flash control.

Is it something that you get used to and get lightning quick at?

IMO it's not especially intuitive (eg. lingering on the zoom button etc.) but OTOH there are a lot of variables to set - I would say that you get used to it with practice.

It's something to consider when choosing off-cam radio triggers, as some rely on Canon's flash menu screen and others provide their own screen/input system.

On their 7DII Canon have slightly improved speed of access to the flash menu screen compared to previous iterations.