Exactly the reason I'm not gunna pick up Samurai Prowl. Yes, it's cool. Yes, it doesn't come with the Traffic Light Of Doom. But it's another $30 for essentially the same thing, and I'm very happy with the original. I'm not complaining about it - if others choose to grab it that's fine - but I'm voting with my wallet.
Actually I've always liked Treadbolt. But as obscure as he is, what really turned me off is how lazy the repaint is. Just as Mudflap has that awful white/yellow mix instead of Erector's grey/yellow, Treadbolt has all that brown - the original had none, and I don't see any compelling reason for a blue and yellow toy to have brown (black would have just looked a lot better).
Tabias, I feel your pain. Repaints are always going to be a part of the Transformers line, but since Armada's flood of randomised repaints (BTW, when Hasbro announced that line, they proudly proclaimed there would be _no_ repaints), there has been a trend of uninspired repaints (such as the Energon Energon repaints Gok mentioned) and some really lazy implementations such as Treadbolt & Mudflap.
When it comes down to it, vote with your wallet. That's the most powerful statement you can make, since Hasbro are interested in your $$ more than your experience after purchase (TT to a lesser extent, they do put a little more value into customer experience).