Used a "pair" (2 adzes) for a day on Great End, and climbed Chimney Finish at IV 5 (turf/mixed route), so it is possible to climb to mid grades with them.
However, it was definitely hard work, pumpy and painful - swing isn't great, they were too long, leashes were a faff, picks had a tendency to get stuck and definitely not enough clearance (massively bruised knuckles). Climbing with DMM Rebels the next day was a huge improvement (despite them being one of my least favorite axes).
Great axe to use as a single on a walking/easy routes day, otherwise, there are much much better tools out there (I now use Quarks).
Finally, with the price of Evos as they are (£80 per axe cheapest??), it's probably better and not much more expensive to get a set of DMM Flys or a second hand pair on here.