This is my first set of carbon wheels and the weight, strength, rolling resistance is phenomenal. This was a huge upgrade over the stock wheelset that came with my Cervelo and saved 500+ grams. I bought open box so the price could not be beat.
Having over 1000km on the EC70AX wheelset i can confidently say its a great deal! Having used premium wheelset (ENVE G23 and EC90AX). The only difference is the EC70 are about 90 grams more.
That being said the EC70 having 28 spokes is a more robust wheelset compared to others. So if durability is of concern the EC70AX is bomb proof