How much are you paying them to swap out the 105 for Ultegra? Here in the States a brand new Ruby Expert is going for about $2600 (before tax) and can be found for less when lbs's have sales (I've seen sales of 10% - 12% around here, which brings a brand new Expert down to your used Comp price) - same carbon frame as the Comp with Ultegra brakes and derailleurs. The Comp has the Mavic Open Sport wheelset, whereas the Expert has the Shimano R6600 Ultegra wheelset - I know nothing about this, but I would think the Expert would have a better wheelset. Also, the Comp has the FSA Goassamer Mega Exo crank, whereas the Expert has the FSA SLK Mega Exo crank. Again, I know nothing about these either.

Anyway, all that to say, for just $300 more you are getting a brand new bike and don't need to pay for components to be upgraded. Also, I would assume you are getting a better wheelset and crank. Not sure if that is worth $300 to you, but something to consider.

Also, you might want to check with Specialized to find out about the warranty (see if there is any difference between the warranty you will get on the test-ride bike as compared to a new one). I think most warranties apply only to the original owner, but I don't know how that works when you are the first buyer (original owner), but the bike has been ridden as a test-ride bike before . . .

Anyway, good luck to you! I've test-ridden this bike three times at three different lbs's and on three different sizes - sheesh! (I won't go into how many other bikes I've test-ridden as well). It's a very nice ride, I just need to find the right size before I make a decision. From my experience, this should be everyone's TOP priority - the right size bike for YOU.