Generations is still shipping, so there's no reason you shouldn't see them at Target and WM (TRU is stuck with too much old product right now). I also saw Thundercracker getting bought at WM a couple days ago.
Roadbuster is definitely a figure you need to have time with, 45 complex little steps each way, and some of it is in the wrong order, vague, or just incorrect, and out of the box it's a disaster of inobvious mistransformations due to... well, I don't know why the factory did those things actually, didn't have to be that way. It's not a shabby vehicle mode, although even with all the paint it has, the deco is weak compared to what the movie design asks of it (I've seen photos of the movie design, not the movie itself - that's a point of pride ). The robot mode is... well, let's just say that Tycho's overenthusiastic gushings about this figure are once again based on his hopes, since he hadn't opened it at the time of the post (and I believe still hasn't). Ok, let's also say that the figure has some good stuff going for it, but also shows signs of some of the weaker elements of Human Alliance, such as a mediocre waist design, and wonky shoulders, and loose kibble parts, and inaccuracy for no immediately-obvious reasons.