get the SS, I have had my steering shaft do the same thing, I got over 40,000 on the first set of brakes and I dont drive it easy...
I have had it flashed, a CAI, some other little things and it Fin GOES.....the old SC GTP Grand Prix dont stand a chance, nor do GT mustangs.....I just smile as my kids wave in the back seat watching TV.....
As for fit and finish, it is top notch over the G6, or old Mailbus, and dont compare a 04 with a 3.5 to a 3.9, the 3.9 are Push rod Technoligy, tons of low end torque.....the 3.5 used electric assist stering ALLLL SS will be hydraulic, its sharper, and handles the extra power and torque better..
The SS is not really comparable to any 08 of non SS malibu, it kinda stands alone, it will roast any other malibu, and has features different frm the rest..from suspension, to steering, to stereo...
I wold go to an 08 just based on 'class' appeal, for sporty driving with some room for the family, take the SS....
As for some other posts on here, Premium gas, Mine will do MUCH better milage on the highway with premium even running it at 140-160kph, I still maintain about 35 MPG, this is Canadian so you have to convert, is it worth it, not really cause it more expensive, HOWEVER you will FEEL a diffrence in the car running premium....
The biggest downfall to the SS is the 4 speed, that is the MAIN reason I had mine flashed, first trip on the highway it topped out at 155kph, not that it would not go faster it was redlining......at 120kph it would rev almost 2800RPM.....so I changed a few things in the flash, ( I work at a dealership and had the tech do it all)....anyhow, now it has longer legs so to speak, sharper shifts, more torque and power, and hauls ass..
all this being said, to be honest it is thirsty in town, but again I DRIVE mine, highway no worsethen any other full sixe car witha V6
1st gear It gets 80kph
2nd ....to about 130kph
3rd.....hits 165kph...
4th...not sure ran out of road....but it doesn not govern anymore either.
anyhow take the Ss it is a awsome car, The only other consideration I may give would be the new G8...the G6 is well not a great car...it did after all replace the grand am.