I'd definitely recommend checking out the EX over the MK4. MK4 does a ton of things but I rarely use it because I have to RTFM every single time I want to try to use it. I'm planning to trade mine in for an EX eventually as I think it will be more user friendly.
-loops
-- looprication
Yes. I have all the Mk4 cheat sheets printed out in color. I find myself HATING the interface and never can remember which knob to push, twist, or turn in what order to change some parameter. That EX is just the right price. Also it will respond to MIDI CC inputs if you want more real-time controls. There are quite a few useful videos on Expert Sleepers website/Youtube that show off the EX's functionality and it's superiority to the MK4.
I don't like to remember key presses, numbers, etc... so I end up hating the Mutable stuff... trying to remember what exactly each symbol and LED corresponds to. It takes me right out of my modular mojo to have to look something up. But that's me. Everyone is different in terms of ergonomics and ease-of-use.