I had the MKS Urban Step-in B and Lambda combination for a while. These are my thoughts:
I really did not like the Step-in B pedals. I am a Time ATAC lover and that fact that the MKS used the same cleats was a huge plus. However, I found the break-in period for the Step-in B pedals was incredibly long. I messed with the spring tension. I was using well broken in cleats. But it took a long, long time before the the clip-in was smooth. At the beginning, I had to jam my foot down, forward, backward, every which way to engage the cleat. Once that issue resolved itself over ~20 rides, they were better. But my goal was to swap between mtb'y pedals and flat pedals. On the trail, the engagement was no where near as nice as my Time ATAC. So, I just gave up and sold the setup.
That said, if your goal is to ride roads and occasionally swap pedals, its fine. Maybe not perfect, but fine. One thing you can do is find the discontinued Non-Ezy version of the MKS Step-in B pedals for cheap on eBay and try them out. Actually, I may have a set missing the dust cap if you are interested (I bought them for parts).
I wish they had partnered with Time and made the basic ATAC pedal with the MKS Ezy Superior Axle. I would have kept that setup forever.