I'm sure you know which way answers will lean on this board, so I'll weigh in from the other side. Don't get me wrong, I love the V from a driving standpoint, but qualitywise it cannot be compared to the $72k E39 M5.
Everything in the car (not just the oft cited cheap interior) is put together to the same exacting GM standards which seem to be applied equally to all their cars. Put aside the raw, visceral driving difference between the V vs. the smooth power delivery, sophistication of the M (which really make them poorly suited for direct comparison).
Having owned a second-hand E39 540i sport for nearly 5 years (all of that time out of warranty due to mileage), the BMW proved near flawless, with the exception of a few electrical parts (HID ballast, CD changer, etc). No engine flaws whatsoever in nearly 70k miles of driving (leaky plastic radiator end tank is my only memorable problem). P.S. I can assure you I didn't drive it like a grandma (pile of tire receipts should prove that).
Having done all maintenance work myself, I was always impressed by the engineering and how solid the car was put together. Paint, body panels, even plastic underhood parts all felt more substantial than the V (I'm not sure if the sheet metal is actually thicker, but I perceived it to be), doors clunk shut solidly, etc. I once hit a deer with that car dead on frontal at ~25 mph and it slid up over the hood like Bo Duke -- leaving barely a ding and a few scratches. Obviously GM did upgrade the base CTS to the V to make it feel like a tank, but to beat the Germans at the performance game at a lower cost.
To make a fair comparison between M5 and V, you really need to compare apples to apples -- warranted V vs. warranted M5, or both out of warranty. Do you want low cost, raw power or do you want a solid, well engineered German tank/autobahn cruiser.
True, M5s have issues with VANOS, weak clutch, and a few sensors. V has issues with rear end of the powertrain, and quite a few minor service bulletins. Honestly, outside of warranty, I'm not sure I'd feel more comfortable than in a V than an M. I test drove M5s, and didn't feel the engine was rough at low RPMs or the steering was imprecise or lacked feel. Interior diffs are what you'd expect for the cost difference when new.
Look back on M vs. V threads on this board, and you see lots of favorable words about Ms. If GM gets the quality of the V up, and ratchets up the power, while keeping price down, the V has a very favorable future competing against the Germans. As the auto rags said, its a hell of a first try, and alot of fun to drive. A better feeling shifter (sans CAGS), more rugged driveline, and better interior would leap this thing into a whole other realm of popularity.
I still say buy the V, and curse GM. You won't be sorry, but if you want smoothness or high quality, buy the M and don't worry about slight performance differences.
Brian R.
