I bought a CAADX 2013 (105 groupset) as my first foray back into cycling since I was a kid. I love the frame and geometry; light-ish, direct and responsive, but would agree with the comments above re brakes. Although I don't have any experience to benchmark against, mine do seem to judder an awful lot and it seems to be a combination of both pads and rims. Swisstop greens have just been ordered so I'll report back on any improvements...
Oh, I too paid £750 in August (down from £1100 RRP).