air setup speed questions

ok right now i got 1/4" port firestone bags, with a single 5 gallon 1/4" port tank running to my whole system, 3/8" line mostly but reduced to like 1/4" at each set of valves because the last owner didnt have the right fittings.. the valves are mounted pretty close to the bags i mean, within a foot i guess..

my question is with 1/2" valves and 1/2" line, running from their own port on a 12 gallon tank, with the valves mounted in the same spots, even with the 1/4" bag ports will this setup be faster? also would mounting the valves on the tank slow it down noticeably?