I bought the v3 and had difficulty assembling. The footplate mechanism wasn't machined correctly and I had to use a steel file to adjust it. TOG support through the assembly was great, I don't have any concerns about their attention or expertise. TOG were good to send me the v3.5 backrest support. The pendulum is very smooth in use, I had to make decisions about counterweight and footplate adjustment. I feel that the perceived weight is even at top and bottom with two 45's on the counterweight. The footplate angle should be adjusted so that your heel doesn't lift during the movement. TOG did not give me any guidance on where the footplate should be adjusted from front to back so I use on of the positions closest to the front of the frame which makes my tibia perpendicular to the footplate during the movement.