I own 2 e-crt.5s and the hexes are way better on that car, for that matter I also prefer them on my lighter cars too. If you run even a mid power motor with pins that car will tear the pin slots up on high traction tracks and the pin wheels tend to wobble.
Hex all the way. When the rims are new and don't slide as well over the axle, it can be a real pain to get the rim on the pins right. Hex rims are much easier to deal with. No more pin accidentally sliding out when take off a rim. Pins are a stupid design.