if you are talking combat speed... it will get faster later, but not because the combat speed, because you will start doing skill weaving a lot later on, so it will feel faster (by miles)

as for story/quest pacing speed... it depend... i guess? if you are not into story thing

vanilla (ARR) story pacing definitely the slowest, because its the starting point so they need to introduce you a lot of things. also the "danger" plot didnt reach you until somewhere 3/4 of the ARR storyline so before you reach that point, everything feels like your standard "adventures / slice of life" story which can be boring for some people. but i give some leeway for ARR story because its the first one so i cant be mad about it.

HW is where things getting interesting, starting HW you will notice a lot of less "filler" and more focus on the main plot, it still has some "relaxing / why we doing this?" part, but at least its not as much as ARR

SB is a step down for me, the main plot is interesting but the way the presenting it.... its basically ARR 2.0

SHB? sit down, have a good drink beside you and some snack, and get ready for a wild ride. you are basically playing another FF within FF lol