I have a Specialized Tarmac Expert, 49CM, XS.
I picked it simply because I wanted:
1) A bike that was fast and responsive and that WOW'ed me the test ride- which is did!
2) A bike that was full carbon- which it was, except for the handlebars, but I put my carbon ones on already.
3) A bike with full Ultegra components- not a mix, but full- and it had that too.
4) A bike with a nice color scheme- and it was so pretty!
I test rode the Giant carbon, but was't WOW'ed by the ride. I also test rode the Ruby and liked it as much as the Tarmac... but it was $400 more... so I took it out of the running.
Thus far, I have only ridden my Tarmac 25 miles... dang weather! But so far... so good.
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather, to skid in broadside thoroughly used-up, totally worn out, and loudly proclaiming: WOW WHAT A RIDE!!!!"