Not asking about the purchase of the Coltri compressor per se but would appreciate any recent first hand experiences from those with this compressor in terms of air quality....specifically have you ever tested for CO and under what conditions...portability would be great but not if I have to be concerned about high levels of contaminants in the cylinder air even if I am scrupulous about where and how I run the compressor and equally meticulous about servicing and filter/lube changes...in short even if I use the gas model very carefully, is the CO level going to be an issue; especially on dives at 4+ATAs?