Well it does take three attacks to complete, unlike a typical autoattack reset (like say the comparable Twin Bite). AS slows kinda dick with it, among other potential problems.
At any rate, the CDR and damage boost are significant, as is the mana regain and damage per rank on Lightning Field. Thundering Blow might be equally good but Acceleration Gate doesn't gain much of anything per level, that's why W > E.
R should come last because you really don't get much of anything from it. The extra on-hit damage going C->H is weak compared to what your other spells get, not to mention a longer cooldown, and the shred gain from H->C is insignificant. The extra resists in Hammer Form is nice but it's not really your "primary" form, no? --- "Pokey and the man."
I also skip out on R but I get E maxed sooner. I'll try W sometime. The manaregen is probably nice.
Never get W before maxing Q and E imo.
the damage output made bycthose two skills is insane and a useless aoe and like 8 mana back per hit isn't worth the loss in damage
W in cannon form lets you kill a ward as it's placed... I dunno if that's something that you can actually force into happening as anything but ADC or Jungle Jayce, but the skill does have that use. --- "That is why war is so tragic. To win means to make victims of your opponents and give birth to hatred." - Kratos Aurion, Tales of Symphonia