With a regular level 7 retro valve and a higher input pressure with good flow rate, you will increase your reactivity.
Adding a level 10 bolt actually reduces your reactivity because it reduces the differential pressure between tank output and the front chamber.
The ULT was also designed to reduce reactivity. Because it you can tune the ULT, you can adjust some of the reactivity back into it while reducing your trigger pull force. It requires modification on some of the older retro valves.
The classic valve isn't reactive at all. It regulates air before it gets to the on-off top. The reduced pressure is the same as using a lower pressure tank when dealing with the reactivity. You can use a retro on-off assembly in a classic valve. It won't increase reactivity, but it will reduce the trigger pull force.
I recommend all mags use a level 10 bolt. Never having to worry about a broken ball and the shooting inaccuracies it causes far out weights the need for reactivity.
Except for the Automag in front, its usually the man behind the equipment that counts.