The measurable difference would be exceptionally small, so much so that I'd argue only a super human would distinguish the difference. All things being equal, with nothing but a battery swap, 99.9% of the population wouldnt detect anything. Not saying you cant or didnt, just that the measurable delta is minuscule.

Regardless, the above setup should provide a reliable platform to build upon. If when the Savox fail, check out the Hitecs. The 7955 is tough to beat, is cheaper, more reliable, and backed buy the best customer support in the industry. If funds permit down the road, step up to the 7950/40s or the new brushless series (priced exceptionally well for what you get).