I made the switch from the Serpent Eryx to the Photon EX and so far have found the Photon EX to be very good. My diff has been leak free using standard components and green slime. The plastics seemed reasonable in the kit and overall I was happy with the way it built. The highlight for me was that tuning it was very easy and I was able to find the grip I wanted after 3 or 4 runs. I went straight for the alloy servo hanging style mount and some different springs but apart from that it is pretty much as per the box.