Mr. Paintball USA Has been burnt by the recent San Diego fires. However, the field are still quite playable. Due to the fires, the courses require much more fast paced gameplay because it has turned most of the shrubbery into sticks which provide, obviously, less cover. This is a great field to go to. Weather you play with the beginner walk-ons or the intermediate players, it is just fun. You wont find a field with more friendly staff and players.
The only down side to this field is that they dont let you bring in your own paintballs. This makes it a little bit more pricy but it is worth it i think because of all the positives. The park's prices for rental guns, gear, air, play are all fine and they are generally good prices. The only thing that costs is the paintballs. My recommendation is that you bring some of your own paint to the field so that you can keep the price down.
Overall, The field is a very good one. Come here if you want to have some fun. Or if you're looking to improve your skills.