I went to the Planet X bike site and saw that they had a very highly and favorably reviewed titanium bike called the Pickenflick, that bike was also rated the best deal in a titanium bike. Having ridden both Carbon fiber and titanium, and ended up with a TI bike is because there is nothing, not even steel, that rides as well as titanium does, and it will last forever, you also don't have to worry about accidentally over torquing something and crushing the CF or breaking the boss attached to the CF.
Having said that you might only want CF and nothing else, ok, that's fine, but why pick a brand name with a low resale value to it? A Planet X branded bike value will tank compared to others, whereas the (the Pickenflick will maintain it's value better than any of the others will) a bike like the Holdsworth will not tank near as much.
sorry to throw a monkey wrench into your brain but just thought you may not have considered some things.