I wrote my own XMLHttp interface several times back before jquery came out thanks. No, it's not useful writing one, I know because I was there back in the IE6 days.

My point was simple, if it didn't suck, there wouldn't be all these workarounds, shims, essential libraries that every website uses, half bastardised coffee/live/closure/whatever scripts, gulps, glubs, and 1500 different templating languages.