REVlite midsole foam uses computer generated impact analysis to provide constant impact cushioning throughout the gait cycle, with a targeted hexagonal configuration that transfers energy from rearfoot to forefoot. A high-density medial post provides light stability in the instep, along with a plastic T-BEAM under the arch to maintain torsional stability at mid-stance. In our testing we saw some delamination of the glue between outsole and midsole in the heel area fairly early in use. 

Fit
Uppers of the 1500 has a new semi-gusseted tongue that cinches down the midfoot well, with traditional laces that hold tension well. Overall fit is standard in the heel, slightly snug around the midfoot, and generally wide enough in the toe box for toe splay, but the rapid taper might rub some wider feet. Length is true to size.

Comfort
The highly ventilated mesh uppers cool and dry quite efficiently, and the interior surface is soft and seamless in the rearfoot for comfort against the skin (or thin socks). Light padding around the ankle collar cups the rearfoot nicely. Testers found the underfoot comfort impressive for the low stack heights of the 1500.

Responsiveness
Testers loved the responsiveness of the REVlite midsole foam, reporting a snappy feel and quick energy return after impact. The outsole provides full ground contact, and shallow lugs in the forefoot help propel you through toe off. With high mileage running (15 miles or more), testers found the energy return seemed to diminish compared to the start of the run. 

Ride Quality
The 1500 transitions from beck to front very smoothly, with thanks to geometric arrangement of the REVlite foam cell into hexagons of various size and orientation. In the heel, they are larger and wider to attenuate downward forces; in the forefoot they are thin and longitudinal to maintain forward momentum through the forefoot. Longtime users of lightweight neutral shoes will find the medial post a bit rigid, but it’s a subtle effect that many wearers might not even notice. 

Speed
The only drawback to speed is that this shoe is about one-half ounce heavier than its forerunner. However, the weight is still quite light, and everything else about the construction is built for speed. It has a comfortable and secure fit, low platform, just enough cushioning to go full-tilt, strong traction at footstrike, and highly responsive midsole material.