Only complaints I've ever heard about the MP housing:

-March says it won't work with their super-fancy accessory bracket system

-The 1/2" NPT hole next to the T-stat hole is sometimes not tapped dead straight down, which bugs a few people. My housing is like that also. This is because the the tap is indexed at 90 degrees to the as-cast surface instead of machining the top of the housing flat and tapping the hole afterward which would be prettier and more expensive, but wouldn't work any better).

-It costs more than a knockoff (if you're on a tight budget, forget the 7lb weight loss and just use an iron one! It's only 7lbs)