But the most common problem is the surface is unclean(on both printers), and my soap to water formulation not being quite dialed in.
Either that, or don't touch the surface with your bare hands.
There's different annoyances for each; if you calibrate each time X1C is slower to get going. X1C is faster overall on bigger jobs. X1C has weird wifi error-out issues more often. MK4 gets a bit more gunk on the nozzle. X1C wastes more filament. X1C had some issues with retracting filament at first that I printed someone else's bracket design to fix, while MK4 just worked. X1C quality seems slightly better with PLA; MK4 does a slightly better job with PETG.
When wear makes major maintenance necessary, it's going to be easier on MK4.