It looks like the Max series are revised/updated versions of older models (DH-102/Max-2, DH-103/Max3).
I use a Sparmax SP-35C and it's a nice, solid, reliable brush. I've had it for nearly 10 years and haven't had a problem which was not of my own making. The 2cc cup isn't really that much of an issue.
PS: There are a few reviews online of the Premi-Air G35, which is a rebadged Sparmax SP-35.