I personally wouldn't touch the IS350 with a ten-foot-pole. The looks and performance are middling at best, and the value end of the deal is almost completely negated when looking at the G37, let a lone much of the rest of the competition. The good news is that Mercedes finally decided to build a competitive C-Class, but you'd have to be nearly as much of a pillock to end up with one as you would if you chose the IS350. The 335i is good enough, but with the new 3-series coming within the next year or so, can you wait?
If I'm spending the money in this category, I'd go for the 'different' options...
* Chevrolet Lumina SS - The performance, size, and bang-for-the-buck is there. May be "plain" in the Middle-East, but I really don't know. After they took away the G8 here in the US, we've been begging GM to bring the Lumina and Caprice back to Chevrolet.
* Cadillac CTS - Significant updates have made the car much better than launch, but its due for an overhaul in the very near future. I still think its the best-looking car in the class, but that is mostly because it has something the Germans and Japanese lack... Personality.
* Volkswagen Passat CC R-Line - Its definitely the best-looking option here. Certainly, a bit "different." The loss of the 3.2L VR6 option is disappointing, but the 2.0T gets the job done just fine. PLUS: Frameless windows. YEAH!
* 2008 Saab 9-3 Turbo X: The coolest car no one knew about. We want to keep it that way.