I recently bought a Mackie Control plus extender (the old one used) and can´t believe how great it is!
I must add that I mainly use Logic 9 and the integration here is nothing short of phenomenal.
The things I mainly used so far are setting levels with the faders (also automation) and EQing the track.
The MCU in Logic has a great mode for EQing where you see the 8 bands of an EQ at once and can adjust the frequency with the rotary encoder and do the gain with the fader (the Q unfortunately has to be done in another mode or on-screen).
Before this experience I would have never guessed that it takes so much auditory consciousness away to stare at the computer screen. Setting a level through a fader with your eyes closed is a game changer for me really! (overused term for lots of stuff but here really fitting even though it´s such a simple thing)
Sometimes the function you want to control can be a bit difficult to access, but I think with time you´ll get more fluent using the MCU. Also the main functions (transport, fader, pan, automation) are easily accessible.
One thing I should add: I believe for a controller to make sense you have to have a tiny display like on the MCU to show track names (imagine switching banks etc). There are so many out there without it and I can´t imagine working intuitively with that.
The MCU has been updated to the PRO model a few years back, but as far as I´ve read it only differs in looks, integrated USB-MIDI interface and mechanically slightly better faders. Buying a used old one for around one third of the price I couldn´t be happier.
EDIT: I have upped "Sound quality" to 10. Please note that the MCU doesn´t process audio at all. I just did not want the score to be bad because of this. (unfortunately the scoring system does not allow to leave one category blank)