11.1v is going to put more strain on the gun and potentially make it break faster.
If you want the best trigger response: 11.1V
If you want to try to prolong the life of your RIF: 7.4V
You've put a fair amount of upgrades into it, and its your only RIF so I would say go for 7.4v. Or potentially buy another RIF as a backup for when you need to repair your primary.