The lightweight racing flats i have experience with are:
- Saucony Endorphin Racer 2 - -- - 11mm stack
- Reebok Float Ride Run Fast Pro - -- - 20/17mm stack
- Sketchers Horizon Vanish - -- - 20/16mm stack
Each have similar fit and differ mainly in the midsole stack/shape/&firmness
After running the Reebok & Sketchers and appreciating the additional midsole stack my Endorphin is now only used for 200's on the track.
- -- The Reebok has a firmer foam and flat bottom.
- -- The Sketchers has a softer foam(but still plenty firm enough for speed) and has a beveled heal & toe taper/spring for a more rockered shape.
- If you are efficient with a true flat then you cant go wrong with the Reebok.
- Where the Sketchers thrives is its versatility. It accommodates a variety of footstrike/technique because of the rockered design. This could be good for those using for the 10k to 1/2 if their technique changes throughout the race.
Do your research on that Addidas Prime. I see a range of differing specs. So make sure you know exactly what you are getting if you decide to give em a shot. Looks like they have a larger heal/toe drop than the above shoes (8mm?) so depending on your running technique could be beneficial or detrimental.