The 17mm and 23mm is only referring to the hex size. A standard Maxx for instance, is 14mm and tend to strip easily with brushless. If you don't have either 17 or 23mm rims, I prefer 23mm (because of all the rims to choose from), but with all the 17mm rims out, it really doesn't matter anymore...I have a few sets of 23mm and no 17mm, so I just stick with 23.