Yeah normal walking speed in BG2 is 9 units. Normal walking speed in BG1 is 6 or 7, which is painfully slow especially if you played BG2 first. Wearing the Boots of Speed sets your speed to 11, which is not only the same normal speed as a barbarian in BG2, but also the max walking speed the engine will allow for the first game.
If you're using Shadowkeeper, though, it displays the walking speed as 0 if you're at normal speed and everything else as a modifier. Normally, that 0 in Shadowkeeper means 9 units, but different character models have different base speeds. For instance, the shadow thief model moves MUCH faster than a standard character at its normal base speed. So just make sure everyone's at 0 unless they're using a non-standard model.