Brooks Glycerin Flex First Run: Is Brooks' flexible daily trainer bringing something new?

The Brooks Glycerin Flex is a new cushioned but flexible daily trainer joining the Glycerin line up. It packs DNA Tuned foam, pliable knit uppers and a lower stack than the Glycerin Max 2.⁣ But the most interesting feature: the midsole has an S-curved flex groove, designed to allow flexibility and cushion without sacrificing stability and support. Cushion with a more flexible feel. ⁣So how does it perform on the run?...