Vehicle mode looks great. I suppose he scales well next to Bumblebee. His windshields are heavily tinted. The gold paint applications are a little splotchy. He features flip-up headlights and rolls well on plastic tires.
As is typical of X-Transbots, there are a few transformation steps of questionable design. Getting the door panels open, forming the hands, and folding the bonnet back from the head all involved flexing plastic, sometimes with audible crackling. One hand popped off, but it was easy to reattach by its mushroom peg. I hated the feet transformation in particular. It was a pain to rotate and hinge pieces past each other. His chest piece is supposed to tab into slots on his wheels, but it's something you have to do without being able to see the slots.
Not surprisingly, Boost looks really good and definitely hits all the cues of the cartoon character. There are a couple of panels along the waist that are finicky and create gaps, but they're not too bad. The back cleans up pretty well. I wish the screws on his wrists were on the other side of his arms. Maybe I should have gone with the previous version, with the white face and legs, but I wasn't sure about the blue body, and silver metallic paint is marginally easier for me to photograph.
His head is on a swivel and hinge. He has ball-jointed shoulders. The chest piece is prone to separating from the tires and neck when manipulating his arms. His thumbs are fixed. The rest of his fingers are single pinned. His elbows and knees are single jointed. He swivels at the biceps, wrists, waist, and thighs. His waist swivel is extremely loose. His hips are on universals. His legs were really floppy until I tightened both screws on the back of his hips. He has toe tilts and rockers.
His accessories include a pistol, his magnet weapon, a face plate, and an extra back piece for his head. His pistol is blue plastic with some line work, but no paint. It uses a Masterpiece-style tab that works surprisingly well. It can store in the undercarriage in vehicle mode, but is always falling out. The magnet weapon covers his fist and is held by a post. It has silver and yellow paint. I think the alternate face plate is for Hatch.
I'll be displaying Boost on my Masterpiece shelf. He looks good with Bumblebee, Arkose, Brawn, and Outback. I wished the transformation was a lot less finicky, but it wouldn't be X-Transbots otherwise. We're so close to a complete G1 season 1 and 2 line-up.
