Evaluation The Fastwitch CRM – Fast Witch? – is actually two racing shoes: the Speed and the Endurance. Saucony debuted CRM – or Custom Ride Management – in the Trigon. Basically, it means one shoe with a choice of midsoles. The Speed has a single-density midsole, while the Endurance gets a small medial post.
Both shoes have a lightweight version of the firm's GRID cushioning system in the rearfoot, and the Speed has GRID Return in the midfoot. The shoe's outsoles differ: the Speed has a low-profile carbon rubber sole, while the Endurance gets thicker blown rubber.
So, is one better than the other? That'll depend on personal preference. The Speed offers a firm, responsive ride and there's little difference in stability despite the lack of posting. For our money, though, the Endurance is the pick of the pair. It's one of those shoes that feels like a pair of racing slippers: comfortable, yet wonderfully responsive. Saucony isn't known for its racers, but that deserves to change with the Fastwitch. The Endurance in particular is a gem.