And hastener speed for that matter.
I had (and still have) my reservations about mounts in RvR. So far, as a solo player, the advantages are that mounts make it easier for me to clear out XP spots when the action is slow elsewhere and make it more practical to stick around solo zones and partake in task zones that aren't in my realm. There are downsides to mounts, too: you're more visible and casting literally any spell (like caster self buffs) resets the 1 min timer.
However, these are either minor drawbacks (more visible) or likely bugs that will be fixed (self buff timer reset). Starting from the principle that caster speed classes should have some sort of clear advantage to non-speed classes, and also the principle that mounts are supposed to be purely about convenience, I suggest that mounts in RvR move at blue caster speed, meaning 138%. Sure, hastener at 150% is still slower than red caster speed at 153%, but that 3% is almost meaningless. Those with speed and those who group with those who have speed should have some kind of advantage, and having your speed kick in faster when kiting is a very minor advantage.
Historically, speed has also been useful for choosing your fights and getting the jump on enemies, two advantages that don't really exist with hasteners at 150% let alone mounts at 150%. Making both of these 138% would still make them convenient, still make it more practical to hang around solo zones, partake in tasks zones without accessible hasteners, and travel to out of the way areas, but speed classes would not have the value of their speed diminished.
This is exactly what has been done for buffs on this server, so it seems appropriate for speed, too. Everyone is probably in agreement that blue buff pots were much needed but that full red buff pots would render buff classes and classes with spec self buffs a bit meaningless. This is exactly how we should look at speed: blue speed adds some (arguably) much needed convenience but red speed would make speed classes' speed valueless.
Tl;dr Hastener and mount speed should be blue 138% for the same reasons that we only have blue buff pots.
I had (and still have) my reservations about mounts in RvR. So far, as a solo player, the advantages are that mounts make it easier for me to clear out XP spots when the action is slow elsewhere and make it more practical to stick around solo zones and partake in task zones that aren't in my realm. There are downsides to mounts, too: you're more visible and casting literally any spell (like caster self buffs) resets the 1 min timer.
However, these are either minor drawbacks (more visible) or likely bugs that will be fixed (self buff timer reset). Starting from the principle that caster speed classes should have some sort of clear advantage to non-speed classes, and also the principle that mounts are supposed to be purely about convenience, I suggest that mounts in RvR move at blue caster speed, meaning 138%. Sure, hastener at 150% is still slower than red caster speed at 153%, but that 3% is almost meaningless. Those with speed and those who group with those who have speed should have some kind of advantage, and having your speed kick in faster when kiting is a very minor advantage.
Historically, speed has also been useful for choosing your fights and getting the jump on enemies, two advantages that don't really exist with hasteners at 150% let alone mounts at 150%. Making both of these 138% would still make them convenient, still make it more practical to hang around solo zones, partake in tasks zones without accessible hasteners, and travel to out of the way areas, but speed classes would not have the value of their speed diminished.
This is exactly what has been done for buffs on this server, so it seems appropriate for speed, too. Everyone is probably in agreement that blue buff pots were much needed but that full red buff pots would render buff classes and classes with spec self buffs a bit meaningless. This is exactly how we should look at speed: blue speed adds some (arguably) much needed convenience but red speed would make speed classes' speed valueless.
Tl;dr Hastener and mount speed should be blue 138% for the same reasons that we only have blue buff pots.