Suspect C63 is a work in progress as AMG sizes up M3 and tweaks C63 perf before US launch in Spr08 (I suspect AMG's preemptive anncmt of C63 was a bit of a vaporware anncmt in advance of M3, sort of like 997TT 2.0 vaporware anncmt in anticipation of Dino
)....will likely be a more useable car than M3 w/superior tq and a fast autobox (rather than a Luddite manual)....and suspect AMG brakes and 63 motor will prove more robust than BMW's....
Prob that C63 or M3 (and all higher-end/discretionary cars) will likely encounter is slowing US economy, esp for "aspirational" buyers....so lease terms will be key determinants of US sales success...e.g., I vaguely recall that, at time of US launch of M5, one could obtain a $0-down, 2yr lease of M5 for some 20% cheaper than 2yr lease of then-current, but soon-to-be-obsoleted, E55; a much bigger delta than the nominal MSRP diffce...mth lease pmts are critical for the aspirational buyer mkt....
And many potential buyers will also consider stretching/waiting to obtain a more classic sportscar icon like 997S 2.0 (esp if has PDK)....or consider getting a deep-discounted/cheap-lease, new S63 (if one needs a fast, spacious kid-hauler that wives may more readily approve)....
What's always amusing is how car mags (understandably) paint the romantic notion of comparing nuances of various 0-xxx/NBR times (on non-street tires of course
)....but vast majority of buyers have a lim mth lease pmt for which their wife signed-off; and the car is used 95%++ of time for straight-line commuting on imperfect, congested urban roads and for hauling kids and wife around on wkends on similarly boring roads....real-world constraints on both discretionary car leases and relevant perf parameters....