Sgort- I am not really sure if you are talking to me, but I am going to assume so.
When did I ever say pneumatics were more portable? While a small pneumatic with a bike pump is probably more portable than a combustion with equal power, pneumatics as a whole are less portable. Also notice how I said-
"except if you are using compressed air of course"
While I did say compressed air I would hope you are smart enough to figure out that I was referring to compressed gas of any sort, like CO2. So I was in no way comparing how long propane lasts to how long CO2 lasts. I would like to see a propane tank last longer than a compressor though, but sadly enough I never am.
I did not bring up portability in my post for a reason. I was sying the pros of pneumatics and portabilitly is not one of them.