Is the riding turtle actually affected by things like glove enchant and crusader aura now? Both of which are simple enough to check. I was looking at the Wowhead tooltip and it seems it functions in the exact same way as the sea turtle and reins of Poseidus, with the latter not being able to be summoned on land. Something to check out is if the riding turtle gives 270% speed in Vashj'ir. Kind of funny if a level 1 can move at that speed, even if it's only in Vashj'ir. I also saw some glitches where people mounted in Vashj'ir then ported elsewhere, and maintained their speed. That has probably been fixed by now, or never worked in the first place, but something else worth trying out too.