Couldn't find a thread on this so I wanted to show them off. Got the red ones for now since I currently only have Bluestreak since I couldn't decide if I wanted to commit to this mold. It definitely solves my main gripe about how stumpy they looked, I think he looks much better now. Nothing much to the items themselves as they're just 3D printed pieces, my only negatives are the red doesn't match as much as the preview pics did and the back of the leg filler piece doesn't lock in very securely, it falls out pretty easily.
I forgot to take pictures of it, but there's an extra piece for vehicle mode storage that turns them into cannons. The only thing is you have to take them off each time you want to transform it, there's pictures of it on the page listing; Ratchet Studio ROS-010 Upgrade Kit for Siege Barricade / Prowl / Smokescreen / Bluestreak (Hip Extensions / Propellers ) Not bad, you just have to pop the legs off the swivel (on mine they were on there very tightly which was the hardest part of the whole thing) and then these pieces plug into the original thighs, and they have a cutout to attach to the original swivel.