The MK wheels really are ONE of the best examples of "ya get whatcha pay fer"....they last a very long time, have very good bushings that don't wear rapidly, and have a very good fit, so there is less airborne noise from wheels rattling.
If you fly a fixed gear plane with pants on (not yours ), have someone hold it a few feet off the pavement, and slowly run the throttle up and down.
If the wheels aren't pretty snug on the axles, betcha a gallon of nitro there will be a resonance point (probably near 1/3 to 1/2 throttle) where you'll SWEAR something is fixin' to come off the plane.
Shut it down, jam some fuel tubing against the wheel and pant, and do the same test.

Let me know what you discover....then, go order really good wheels without much axle slop...