The only part I didnt like when reading up on that MyDX was this:
"For you technical folks out there, the first generation target for MyDx is to be able to quantify chemicals to within 20% of conventional gas chromatography (GC) instrument values. Our subsequent generation devices and sensors will target a marginal error rate of within 5% of GC values."
Seems like it is better to just wait for the second iteration if it will be 4x more accurate.