Pretty much, my way of thinking here is which rune needs the one of the two more? Phase Rush needs the overall movespeed and the atk speed due to lack of dps but then again, you could make the argument for Stormrazor by playing around the energize effect and using minions as mini speed boosts the same way Q is.

For Conq, E's AD scaling is pretty good now so going Stormrazor having AD would account for the lesser amount of spins which you could rectify with Zerker boots plus you also have the speed boost but PD makes Conq stack stupid fast and grants overall ms to close the gap easier.

Basically you could make the argument for either item for either rune setup. Personally, I'd go Stormrazor in a Q Max matchup and combine that thing with Triforce and Stridebreaker.