Ive used both and i much prefer a seperate octo. Ive had to use the air2 in a simulated OOA and it was a pain, even just as a practice, and I have had to use a seperate octo in a real OOA situation and it is much easier because your buddy can just grab your octo, you dont have to worry about them ripping your reg out of your mouth, not to mention, often they are a little paniky.