So I've got all of these so far, and am eagerly awaiting the Not-Motormaster preorders to go up.
Brief thoughts (in order of release)
Car Crash (Not-Breakdown) - Second best of the lot. Car mode is a Lamborghini hybrid, closest to Aventador. The transformation is worryingly tight, you're going to get scraping between the outer hood pieces and the inner pieces, which are painted red, so watch for scratching - I've got none so far but am paranoid. Bot mode is fantastically poseable and very stable.
T-Bone (Not-Wildrider) - Remold of Car Crash, but you can only really tell in bot mode. Car mode looks like a Corvette type thing with added bodywork and doesn't hold together as well as Car Crash. Transformation feels looks, especially the legs. Bot mode looks more or less the same as Car Crash but with different shoulders and chest. Gun is worrying tight in his hand - these have Prime style open hands. No stress marks yet, but I'm worried, as always.
Down Force (Not-Dragstrip) - Not even going to try and pretend I know what this car is - colours are really nice though, the aqua on the shoulders/lights really pops against the bright orangey yellow and metallic silver. Transformation is all standard except the shoulders/front of the car, which are quite finnicky and end up quite unstable in both modes. Bot mode is not as poseable or stable as the others. The weakest of the bunch, in both modes.
Last Chance (Not-Dead End) - Best of the lot. Car mode is a Ferrari FXX (I watch Top Gear sometimes, what of it?). Transformation is fairly standard, and nothing feels too tight or loose. Instructions miss a step about clicking the crotchplate back in car mode to give it rolling clearance. Both mode is a lovely mix of dark red and gunmetal. The car parts hanging off the arms lend it a slightly shellformer vibe, but overall a very nice execution.
Overall thoughts so far - the only ones worth buying on their own are Last Chance (definitely worth picking up if you're not getting the set) and Car Crash (just about worth picking up if you're not getting the set).
Lots of tiny parts and force required - I had the set of them on my desk this morning and went from robot -> car -> robot for each of them (so 12 transformations in all) and now my fingers hurt from pressing tiny sharp bits of plastic into eachother
Possibly more detailed thoughts coming later on if I can get a nice dark backdrop for the shiny black glass dining room table we now have for that photobox effect.