Yes, of course, because network latency is probably almost the same to almost all sites to you. So the vast majority of pages take 400ms or whatever to load, and you don't think anything of it. You only notice when you hit a site that's out of the ordinary — whether it's Google loading in 85ms by using IW9, or Twitter taking multiple seconds to query the snail farm or frozen molasses or whatever it uses for its database now that it's dumped Cassandra.

If IW9 or IW10 gets widely adopted, you'll find yourself thinking "this website is slow" when you visit the rare backwater that doesn't use it.