Statikk vs. Rapid
Why wouldn't all ADCs just build Statikk since it CAN critical? Standard ADC build has loads of crit so Statikk will be doing more damage overall, Rapid isn't making you any safer if you still have to stick to your normal attack-range after the charge fires
Rapid needs something more, and more importantly different, to accentuate its 'safety' and long range attribute.
Shiv - Burstarino lightning bolt PD - Kiting and dueling power for your vaynespotting needs Hurricane - On-hit and stackers like Kog, Varus, etc. Rapid - It's Shiv but without lightning.
I think Rapid should have a "heat-up" counter similiar to right now, except at max heat-up you can activate it to gain the attack-range buff for a few seconds instead of just one auto. Get rid of the stupid mini-shiv and give it a real purpose