Here I go with my elitist attitude again...
His handle is "Ontrack." He consulted James Clay, a professional race team owner and an accomplished racer himself. The three brands he cross shopped, MCS, Moton, and JRZ, are all professional grade RACE dampers.
I don't think ride quality is the first and foremost on his mind. Just a guess.
IMO, when you're talking about the stratospheric level in terms of PROFESSIONAL race quality dampers, there are so little difference in how they're built and their quality and function that it literally comes down to personal preference and professional obligations. Now, having zero professional obligations to neither company, my personal preference would be MCS because the company I used to work for looked into a bid to buy Moton's US distribution rights and was turned away before it even got to due diligence. Not that there's anything wrong with Moton. It's just that I am still bitter that we didn't even get a chance to submit a bid, but that's water under the bridge, so they say.
But. I am fond of saying, that if you're going to buy ANYTHING in the automotive aftermarket, you should really know why you're buying it, and why one product cost more than another...Basically, you should really know what you're buying FOR. The key reason why the Motons and the MCSes and the JRZs and the Ohlins in the world cost so much, isn't because they're superior shocks. Oh, they're superior. But they cost so much because they're RACE dampers designed to be REBUILD at the end of every season. Most professional and amateur teams running these dampers will have them removed, and sent back to each respective brand's facility (or the likes of James Clay at Bimmerworld) to have the internals re-valved and rebuilt. Because "racing" puts such incredible amount of stress on the components that by the end of a single (or two, depending on how many races you enter) season that most of the internals would require reconditioning regardless of what brand of shocks you use.
So you MUST ask yourself. Are you buying MCS or Moton because they're better shocks (oh believe you me, they are), or are you buying MCS or Motons because you NEED them. In all honesty, you're paying for the better internals and the race development behind the product, not necessarily better or stronger material. The best analogy I can give you, as an amateur camera buff, are guys who paid $8,000 for an advanced professional DSLR system with another $10,000 invested in lenses, only to leave the camera in "program" mode and basically POINT AND SHOOT. Yes you're paying for a world class, professional camera that can do some amazing stuff. But in reality, all you need, at best, are the prosumer level camera because frankly, you don't have all the associated professional equipment to take full advantage of the $8,000 pro camera.
Now, off on a tangent. I am an avid amateur photographer and COULD probably eek out a living doing that. Recently I art directed a photoshoot for a client with a friend of mine who's a fashion photographer for the good part of the last 30 years and is universally pegged as the top photographer in his field. He's got a phenomenal setup in his studio. I did a mental tally of the equipment outside of his cameras and lenses, and it probably exceeded $40,000 worth. But the ONE tool he has at his disposal, that he took extra care for more than anything else in the room, that I don't have? His color card. A $100 piece of paper. He wouldn't let me touch it. I can go off on more tangent about how he shoots with controlled light and I shoot with available light due to the different subjects we shoot, but that'd be boring most of you who are not into photography, but that was the one single tool that caught my eye that makes it having a professional level camera worth while. A color card.
Frankly I don't know why I'm telling you all that stuff. Maybe another analogy that would suit better. For someone who's never going to see track use on his MZ4, choosing between MCS and Motons is like trying to decide between a night with a couple of $10,000 high-end escort, who most likely won't put up with fellatio and using other parts of the body not entirely designed for giving pleasure, while all you really want and need is a night at the Bunny Blue Ranch for $1,000. Sure, the end result is PROBABLY going to be similar to you. Sexual release and satisfaction. But frankly? The girls at Bunny Blue Ranch will probably do a better job with the fellating and might even open up the possibility of using other orifices for your use than the high end escort.
But do know this. Either the MCS or the Motons will likely be the BEST dampers you can possibly buy, just like the $10,000 escort will look damn nice as you two stroll down Beverly Hills and all the on-looker wonder which movie star you are.
