This is my racing bike: a Pennarola Acrux XR Limited. Originally, I got it mounted with a Shimano Ultegra groupset, and Mavic Ksyrium Elite wheels.
but I quickly realized that this setup was not exploiting the full potential of this bike.
The carbon-kevlar-titanium monocoque frame with integrated seatpost is quite rigid, and returns everything you give. It deserved an upgrade, and therefore I just had it mounted with Shimano Dura Ace wheels (WH-7850 C24 CL),
as well as the new Dura Ace Di2 electronic groupset.
After testing it for some time, I have published my comments at the following link.
The outcome? With only 7.6 KG in XL size (fully assembled, including pedals) that bike is superb.
I just love it!