Powercore 10k (Reg vs QC 3.0 vs Speed QC) for Apple devices

Hi,

Just wondering if anyone is able to briefly summarise the key differences between the 3 variations and if one would be better suited for specifically charging an iphone 6.

From what I can tell when it comes to charging capability with respect to iphones they would all perform the same and the (speed qc) just has improved safety features whilst being slightly larger? Currently the price of the QC3.0 and speed are the same with the original being £5/10 cheaper.

Would the speed be the way to go being the current iteration and slightly more future-proof? Is it even possible that apple devices could support these QC features in the future or is it limited to snapdragon androids?

Thank you