I also never put too much thought into it. I re-jetted and put in the 140 e tubes before I even rode my bikes. So I wouldn't know if there was a difference. Never bothered to try the stock e tubes. The bikes run well.
I should try the stock e tube on my stock bike with the 33 main. It's possible that the 140 e tube is too much for a jet that size. And the autolite plugs you can't really get a good read on.