I think I have a potential calculating job for you, if you would like to take it on. I think a lot of players would benefit from a post about speed! I'm talking horses vs. speed-increasing foods, the rates of increase, and riding vs. walking while foraging (the speed increase minus the split-second it takes to get on and off you horse). I certainly would love to know what you have to say :)
Speed bonuses stack with the horse speed bonus, so the comparison is moot. Having said that, the combination of Coffee and a food item that gives a speed bonus like Pepper Poppers will (or at least used to as of 1.2) stack to be faster than the base speed of a horse, and will function indoors and in caves and through gaps that horses cannot navigate.
Thanks for the Beginners Build Order in First Spring guide. After playing 200+ hours it made the game interesting again. And more efficient ;)