Small tank higher pressure? or large tank Lower Pressure?

I was think what was better? a Small tank with a higher pressure? or a large tank with a Lower Pressure? Of coarse if you had a small tank you gun would look better. This is how air rifles work... you break the barrel (push it down) and that push a pump in to a small tank at a high PSI, Thats why its hard to break the barrel. I was also thinking that if you had a Higher PSI in the air resivour it would release quicker?!. What do you think?