Speech to text on A7 powered devices

Hi there everyone,

I am a constant user of speech to text on my iPhone 7 And previously my iPhone 6 as I struggle with arthritic hands And it’s much better for me to dictate than type. I love the speech to text feature on iOS and was considering using it on iPad as well. I know it worked well on my iPhone 6 which was A8 powered. My question is how well the system works on A7 Powered iOS devices such as the original iPad Air, the iPad mini 2 and iPad mini 3 etc. Does anyone have any experience of this or have any of the above devices and would be willing to test it for me please?

Thanks :)