> everyone should just have a full face gas mask for all hacker-ish activities, like painting

Not everyone who wears eyeglasses, unless you're prepared to add another several hundred dollars for the lens holder and set of prescription lenses.

I do have the 3M 6800 full face respirator but almost never use it. The silicone 7xxx series is much more comfortable than the rubber 6xxx series, and the 750x silicone half mask is reasonably priced. Augment with comfortable googles as necessary (vented ones work for me since I'm painting, not rioting).