Built to order? Hardly. A generic carbon frame, screwed together with commercially available parts. Brilliant value but nowt special.
Dura Ace is a £600 groupset and Planet X won't be selling them without making a profit, so corners have been cut somewhere to bring it in at £1000. Personally I'd rather have a lesser groupset (which will wear out eventually and need replaced/upgraded anyway) and have a bike where the money has been spent on the frame and wheels. It's those two things that make a good bike, everything else is just there to point it in the right direction, make it move and give you somewhere to sit. A cheap frame won't ride any better when equipped with Dura Ace.