I wear 1/2 size smaller in Rincon. Clifton 12.5, Rincon 12. David * Ironman for Life! (Blog) * IM Everyday Hero Video * Daggett Shuler Law * Disclaimer: I have personal and professional relationships with many athletes, vendors, and organizations in the triathlon world.
I have done about 200 miles in the Rincon 2's. I dont think they will last as long as the Clifton 5, the upper and sole are less robust. This makes sense though given they are a different type of running shoe.
The arch support is more or less the same. But I find the fit of the Rincon 2 a bit more comfortable because the toe box is slightly wider compared to the Clifton 5. The bottom of the sole is also slightly wider all round.
I actually ended up buying another pair of Cliftons for long run's. I cant do long runs in the Rincon 2's, with 10miles being about the maximum range for me. If you are keeping your runs below 10miles, then the Rincon 2 works well as an everyday trainer. I would also use them for races 10k and below. But dont expect them to last as long as a pair of Cliftons.