Disclaimers:
1. This is only a review of the drivetrain. You all already have your opinions on the interior, etc.
2. I stepped out of my '04 CTS 3.6 auto into the CTS 2.8 manual. This was a direct comparison.
3. I drive my husband's manual transmission Passat regularly, so I'm not a manual newbie.
The 2.8 seemed very rough. Noisy in fact. I felt I was in a substantially lesser car then my current CTS. At 80mph it was turning a very loud 3,000 rpm in 6th. Not impressive compaired to my car, and certainly not better then a S/C Riviera that can silently woosh along at 80mph doing about 2200 rpm.
The gear shift throws are perfect. I was easily able to hit the gear I wanted. Reverse is in the wrong spot, but I think thats were it ends up on a 6-speed. It's German style, hard left and up.
The clutch was waaaaay to sudden. I found it really hard to take off smoothly. Your foot is all the way in, let it out slowly... slowly... then BAM... you're stalled at the light with a semi blaring it's horn at you. I stalled the CTS 4 times on my test drive. The clutch MUST be pushed all the way to the floor.... ALLL the way... before the car will let you engage the starter.
1,2,3 and 4th gears the engine is fine. It's peppy and feels a lot more powerful then it is. 5th and 6th gear and the car magically transforms into Cavalier that hasn't had it's airfilter changed since 1982. Getting up to speed on the highway had my foot completely to the floor... in 4th.
In short, I think the CTS is too much car for the 2.8 to haul around... even with a manual.