The phrase "performance edge" means having an advantage or superiority over others in terms of how well you perform or achieve results in a particular area. Full definition
The 360 has a slight performance edge on previous titles between the two, but not so much as to make a massive difference. (iheartinfinity.com)
Other devices might have a slight performance edge over the new Moto X, but the Pure Edition still manages to feel like the most elegant of the cheap - good smartphones we've seen this year. (smartphone.ninja)
It doesn't carry the same hardened performance edge of a 911or M3, but it sits at the pleasant intersection of legitimate track credibility and Jaguar brand character. (automobilemag.com)