Actually, it doesn't get that slow. I ran benchmarks and avg. increase was 10%. Compared to other things on the internet, it doesn't cause that much of a slow down.
That's... actually a lot worse than I'd have expected. When running a new protocol that <=3.x didn't support, sure, but then the test suite couldn't compare so this must be for old protocols that they just made slower?! Sounds like it would be nice to have a separate code path for the 4.x calls so you can import an older, supported version alongside the new one and call into whatever was available there
