You shouldn't see any differences at all. It might be a bit faster, there's a lot less code executing on each hit. But it should do exactlly what the previous setup did.
I installed the new stuff on Mendota, my virgin setup, booted up yesterday. Seems to work, but there's not much there to test. :-)
Important: In order for the new responder to kick in, you have to: 1. Bring worldOutline.root to the front. 2. Choose Re-install Front Tool from the Tools menu. If it's running you should see new stats in config.worldoutline.stats, such as ctBytesLastResponse and ctResponderHits and they should be non-zero. You can also quit and restart OPML for the same effect.