Motor Trend recently did a comparison of the CTS vs the TL (and the Saab 9-3 and Infiniti G35). The CTS came in second and the TL in third. They didn't have very nice things to say about the TL aside from it's looks. The CTS was just the opposite, they raved about everything and only held it back because of it's polarizing looks.
You may want to read what they had to say:
http://motortrend.com/roadtests/seda...ans/index.html