Mine is mixed: 2006 Roubaix Comp - ultegra rear, 105 front, 105 brakes, FSA crank.
I love it. I'm sure I'd love full ultegra too, and who am I kidding, I'd love dura-ace too, but for the money, this bike is amazing. I tried the model with a triple ring and 105 rear, but this double ultegra rear was SO much nicer to shift. It was worth the extra money..and still reasonable.

I swapped bars and saddle to women's. And I've got the bar phat with the gel pads (the thinner one--2mm I think?). It's great