Why buy a Hallman? It's not like these mbc's break and one needs a warranty. They're so simple they don't fail.

No I'm not familiar with that
www.boostcontroller.com but after reading the description of their mbc and how it talks about an adjustment screw that "if you lose the adjustment screw it has a 2nd ball to close for safety" LOL. That is plain silly and pure marketing. If you tighten up the dawesdevice mbc it isn't going to fall apart.
Bottom line: spend your money on what you want but there is no reason to avoid getting the dawesdevice controller. It's more inexpensive and just as good (if not better than that funky dual ball thing.) Hallman boost controller is fine but why spend the extra 65 USD?
Steve