Inferno is gonna be
really tough to beat, at least for non-keyed implementations. We don't have a keyed implementation from them, so it's hard to say exactly how they do there, but i dont doubt that it'll be at or near the top. For now kivi is likely the fastest possible but the way you have to write your code with kivi is rather unpleasent. However, the whole point of kivi was to push the perf boundaries, not to be useable directly.
At the end of the day, there are numerous <= 15KB libs that come within 3%-15% of Inferno, so the perf and size difference is really becoming secondary to lib ergonomics and features.
If you wanna read a lot more of our convo, head over to: https://www.reddit.com/r/javascript/comments/5m2u0s/infernoj...