The site often never has air unless prebooked far in advance so having the larger tank will let me have it filled at a shop then hopefully do a full days play without needing to hope they have air left. All depends on the day and how much notice i give to have the dive bottle filled
Very important point there
It's easy to forget not every site has HPA compressors on site, and there are a good few that run CO2 still - which means either no HPA or dive bottle fills.
It also means you won't necessarliy get maximum fills. They need to have a higher pressure in the source to maintain fills for the customers. If they have a 3000psi scuba source then you get more consistent fills for everyone longer through the day if you ration to say 2500psi.
If the first gets a maximum fill then the second gets less, the tenth gets a dribble.
If they have a 4500psi source then 3000psi fills will last a good while
If they fill fibres higher then again it should be rationed a bit
DO OF COURSE TAKE CARE with scuba fills. Always fill slowly and make sure that you know if the fill station is regulated or not and especially if not make sure you know the source pressure. Remember 300bar marked on a scuba is 4500psi to paintballers
It is possible to fill 3000psi from an unregulated 4500psi source, but it is dodgy and has to be done with great care.
In this case the bigger the better (Does mean you are getting the lions share at the start)