Even though Mason Pearson makes wonderful hairbrushes, I think their shave brushes are rebranded Vulfix. At least, that is what I have heard. A good brush, no doubt...but hardly worth the money they want for one with so many better options for less coin. Hope this helps.
About two years ago, I bought a Mason Pearson pure badger in my local barber supply shop -- it's held up quite well, losing only a few hairs a month, even as my everyday brush. Still, it is *just* a pure badger brush (after two passes, it definitely feels scratchy) and I'm pretty sure now I could get a better brush for the $60-70 I paid.