I think you'll find if you go to a smoother, lighter, thinner tire your avg speed will increase, maybe 2-3mpg ....depending on variables. I do like Bonrgr Hardcase tires, big thumbs up, but I don't know about the AllWeathers. As an all around commute, training, touring tire I lean toward Gatorskins. Maybe a tad heavier, but the 28s are impervious to bad roads.