I thought about that. But it would have diminished the point I was trying to make: Always test with different versions as performance may differ by a LOT.
He was talking about differences between point versions. 0.10 has dramatically different performance to 0.11. io.js is using 0.11, as is node:master, but older node was using 0.10.
I.e. the difference isn't necessarily node vs io, it's one point release of V8 to the next as used by node and io.