Hot questions for Dan: what kind of running shoes do you prefer? Are you feeling any wear and tear on your knees at the distances you're currently running?
Not Dan, but sneakerhead here.
As far as running shoes, check out adidas' running shoes with BOOST (ultra boost, energy boost 2.0, etc). Boost is the craziest material I've ever felt in a shoe. It reacts like nothing else, and gives you response unlike any other material in a shoe.
https://www.youtube.com/watch?v=nxRmUDX99BU (this is a video about their basketball shoes, but the same material is used in their running shoes)
I have a pair of adidas Pure Boosts (not a running shoe, but a casual shoe with a boost outsole) and when I wear them it literally feels like I'm walking with springs on the bottoms of my feet.
The Ultraboost is their current flagship running shoe that just released, and although it's pricey, you will feel the difference. I'd suggest going to a store and trying a pair of shoes with boost on. Walking around you'll feel it immediately. I've told many people about the material, and they are all instantly sold the second they put a pair of boost shoes on