The Endorphin Speed 5 is the workout shoe in Saucony's fast range. A nylon plate sits in PWRRUN PB foam under a 36 mm heel and an 8 mm drop, which gives you a snap through the toe-off without the stiffness of a carbon racer. At about 237 g it is light enough to run repeats in and cushioned enough to finish a half in.
It suits you if you want one shoe for every fast day of the month rather than a racer you save for three mornings a year.
It is not a super-shoe, and it is not an easy-day trainer either. The plate keeps nudging you toward a pace, which is exactly wrong on a recovery run. Keep something plainer for those.