The lack of performance controls on the MPC Live can easily be made up with an additional MIDI controller. Since the MPC is also a USB Host it´s just plug and play after you´ve done your mapping and there´s basically a MIDI controller for every porpuse/workflow.
And I guess it also depends on how you play live. If you´re “just” switching between sequences or mute pads/groups and prepare everything else in advance then it offers enough I guess but if you feel like adding some layers spontaneously then it really is quite cumbersome compared to other boxes. I still wouldn´t want to miss mine. It´s the center of my setup, no matter if connected to a computer or standalone and I can control, record and arrange everything on it. And my Keystep is only connected via USB to the MPC and I can play every synth that is connected via MIDI…
I also own the Digitakt and can basically confirm what others already wrote, it´s so much more immediate and fun to use. I just love the step sequencer with all the trig conditions and p-locks so to me the DT and MPC are excellent companions since the MPC does the things I don´t have on the DT: stereo samples, song mode, velocity pads and with the added SSD drive tons of storage. The ability to just work without a computer without being too limited was important for me since I already spend 8 hours a day in front of a computer so the MPC is here to stay for my setup.
If I feel like using a step sequencer I won´t even bother with the MPC since the DT is so much more powerful and when I feel like recording a more “humanised” pattern quickly I choose the MPC. Or I just use both together and see what happens…