I have a Canyon Ultimate CF 7.0 - bought nearly 3 years ago via the Net - and am delighted with this bike.
I too, was nervous about buying unseen via the Internet but has proved to be excellent equipment, superb quality of frame and components and a bargain at the price. Am a very happy customer.
Check your sizing with the Canyon on-line tool, but don't hesitate to go UP one size if you want comfort versus out-and-out Sport as Canyon does size 'small'.
You should focus on the length of the horizontal top-tube as your principal reference point for sizing (not the seat tube).
Also check and specify what length of Stem that will fit you as this is a variable.
(I was in a hurry ordering and did not check this). Bike arrived with a 75mm Stem and I found out I needed a longer 105mm, which I subsequently had to order from Canyon.
Order during Canyons Summer Sale
They seem to have a Sale that runs during the Tour de France most years. Not sure if they will do this in 2010 - but worth waiting for. Prices are cheaper. Also, if you order at the start of the sale, they seem to have bike stock available for rapid delivery. (This is not the case either at the end of the sale... Sold out or early in the season when Canyon gets lots of critics over lengthy delivery times...)
After nearly 3 years with the bike - everything is still in great condition. Top quality that you would kind of expect with a German sourced/assembled product . I do my own basic routine maintenance (eg clean the bike), but have also extended to changing the cassette for mountain trips.
Apparently, after-sales support from Germany can be long if needed, so good to be self-sufficient.
Personally, very satisfied with this bike.
(usual disclaimers - I have nothing to do with Canyon).