I bought a new Hobby Air II supplied air breathing system for painting and blasting a few weeks ago.
I tried it out for the first time this evening. I have had a Hobby Air I for years. The hose kind of disintegrated. So rather than just buy a hose, I decided to step up. My Hobby Air I had a half mask and 40' of hose. The pump won't support more length of hose. So I got the Hobby Air II. I got it with 80' of hose, and a full hood. I can say it's much nicer, and the extra hose is going to be a big plus.
If you're considering a Hobby Air, I can definitely recommend the slight extra expense of the HA II and the hood. My half mask can be used with the setup also.