I'm new to this type of paintball. I haven't played traditional paintball in years. I recently bought a new P99 and then bought a used P99 off of ebay. While doing repairs on it I noticed the valves and such did seem a little dirty. The Umarex site says that their air is cleaner. That's great and all but is it really that much better. I would have no problem getting my air from RAP but getting it shipped to your house looks like it can be a hassle. So my question is, Is there a decent quality 12 gram you can get from walmart? Even if it's not up to RAP standards is one brand better than the other? And if there is no good store bought alternative does RAP have a vendor in the south east or georgia preferably to try and curve some of the shipping cost and time?