Yeah, it's pretty Snazzy All Right... The Powered Air Purifying Respirator comes in handy when I am playing with Stainless Steel, or Hardfacing, to cut down on my exposure to Hexavalent Chromium, and other Nasty Contaminants...
I can Air Arc or Weld Stainless, Mild Steel, or Aluminum and smell nothing.... Same with Plasma Cutting or Torch Cutting etc etc, BEST invention I have ever used.
I wear it about 35 to 38 hours in a "Normal" 40 hour week, unless I am in the Bed Truck moving tanks or buildings in and out of the shop.
It makes a nice addtion to the 5 helmets I already have - The 2 other Speedglas, the 2 Baccou-Dalloz (Sperian) Harley Davidson Manual Helmets, and my 1st Helmet from Princess Auto...
Oh, back to the original question regarding a Half Mask Respirator... I can use 3M masks under my 9000X and 9002X helmets with the soft filters, but cannot fit a North half mask with the Backpack (Snorkel kit) to carry the hard cartridge filters on my back...
Without going to a PAPR unit of some type, you would probably have the BEST luck fitting half mask respirators under the new Speedglas 9100 series Hemlet with the fully adjustable headgear.