The 3M is an excellent respirator; you won't go wrong with it. The other that Mike is referring to is the new MSA Advantage 200 series. From talking with MSA reps, this device is going into Home Depot stores, and will be replacing the older AO respirators that have been sold for years. Personally, I think this is a good thing. The new design at the nose, and the light weight silicone mask will make the respirator more comfortable for those who wear them for longer periods. In addition, the cartridges now have a bayonet mounting system that pretty much makes cartridge attachment idiot-proof. IMO, both 3M and MSA represent some of the best respiratory protection has to offer.
Gip Winecoff