Summary: I own the 52', 54' and 58' MP-R Chrome wedge. The clubs are very accurate, with a nice soft feel at impact. I agree with one of the previous reviews stating that the lenght of the clubs is limited (70 meters with the 52') so there is a big gap from the PW (in my case a Mizuno MX-950).
Summary: I have a 52 and 56 degree in black and my 60 degree is in chrome. There is a bit of a yardage gap in between my MP-32 PW and my 52 but it is not unmanageable. My yardages in between the wedges are consistant.
Summary: I've been playing these for about 8 months, and love them, with qualifications. For finessing shots, half shots (incl. punches), and blasting out of "impossible" lies with the 56, I love them. But for full shots, they are quite lightweight. I have to apply a lot of power to get them to travel.
Conclusion: Bought the 56 Degree Sand Wedge and the 60 degree Lob Wedge. Typical Mizuno quality and great understated look about them. They both set up well behind the ball be it on the green stuff or in the sand. Both offer very good feel out of the sweet spot, and very good spin control.