Thank you for bringing this issue to our attention via the community. We appreciate the help from all of you as well@elmo41683 @nigelhealy @thetonyclay @fhassm @joshuad11
All these Apple devices listed in your message(iPhone 6, iPhone 6s and iPad Air) take the advantage of the fasting charging with Anker's exclusive Power IQ charging agreement. Both of the PowerCore Speed 20000nAh QC3.0 and PowerCore Elite 20000mAh support the Power IQ charging agreement. So you can use either of them to charge your Apple devices. However, I would like to provide you with some differences for your better choice.
The PowerCore Elite 20000mAh only supports the Power IQ charging agreement but it has two input ports which can be charged in around 6 hours with two charging input ports.
The PowerCore Speed 20000mAh QC3.0 model supports both of the Power IQ and the Qualcomm Quick Charge charging agreements. However, it only supports the fast charging on output. To charge itself up, it will take around 9-10 hours. But it can fast charge both of your Apple devices or Qualcomm Quick Charge devices such as Galaxy phones if you will have in some day:)
Both of these two batteries are not discontinued. The PowerCore Elite 20000 is just out of stock at this moment. We are still having the replenishment schedule for it.
The USB-C PD model in "Speed" battery that fhassm mentioned is another different model which is named PowerCore Speed 20000 PD. It supports the Power Delivery which is mainly for MacBook or MacBook Pro USB-C devices.
At last, just a friendly reminder that you'd better check the warranty policy before the purchase if you are going to order it from your local store as our warranty only covers the purchase from Anker and some of the authorized retailers. Thanks for all you support again.