Yes, i agree with everything he said. I started out with CO2 and quickly switched over to compressed o2 because during the winter i experienced severe performance problems. Pressure spikes and when the liquid changes to gas form ice shards form and damage o-rings which will need to be replaced frequently. With compressed o2 your pressure is consistant and cold weather has no effect on the performance of your marker. The only drawback is the price. I purchased a 3000 preset psi 68 cubic inch crossfire tank for about $160.