Can't see anything wrong with the M Part headset, for the money. Although I have no experience with that headset in particular, I have used pleanty of loose ball headsets without issue. Most cheap cartridge headsets just come appart in the same way anyway. They might seat a bit better for the 45 degree cartridge shape but that's about the only advantage that I can see (awaits tester to come and school me on that). Also, if you look at the reviews for the Ritchey headset, they're not that good and one states that the "sealed" bearings are actually exposed.
Can't see anything wrong with the M Part headset, for the money. Although I have no experience with that headset in particular, I have used pleanty of loose ball headsets without issue. Most cheap cartridge headsets just come appart in the same way anyway. They might seat a bit better for the 45 degree cartridge shape but that's about the only advantage that I can see (awaits tester to come and school me on that). Also, if you look at the reviews for the Ritchey headset, they're not that good and one states that the "sealed" bearings are actually exposed.