Was wondering if the USDM MR has the MR BOV? Is there a difference visually that you can tell if it is or isn't? I've noticed that my car seems to hesitate for a quick instance when it spools up past 1 bar, I was wondering if maybe these come with the normal evo BOV's and that it might be leaking at higher pressures.

 

usmr has the standard plastic DV. I don't think that slight hesitation you are referring to is boost leaking. Probably the ECU compensating trying to prevent the boost spike and overshoot that usually occurs.

 

It appears that the Evo IX MR has the JDM MR dump valve. It looked metallic in the pictures I've seen.