351MonteCarlo,
Somewhat misleading with your statement , as just saying a 03 is more tuneable and a Gen IV is not , totally disregards the fact that taking the stock computer out and replacing with a MoPar race computer ( letting Dodge/SRT do the remapping ), adding headers, polished intake , etc. and bingo you are at the 700 hp range.
We have done a boatload of Superchargers, and frankly that is the least expensive way to get more hp on a Gen III , but some factory type tuning and a few mods and the Gen IV approaches the power of the SC with less cost and a more usable power band - and for track guys, no heat soak.
Ride characteristics are stellar in comparision , and it is a culmination of suspension tweaks ( our old buddy Herb Helbig gave the green light for the engineers to make some last minute changes prior to the launch of the 08 ) , along with the PS2 tires. Driving on a rutted road seldom causes the severe wandering and the ride is much more supple.
From improvements in the transmission, the engine ( VVT, new oil pump, vastly superior oil pan , higher redline , virtually no bucking when driving in traffic ,etc. ), new rear end, suspension, etc. one could go on and on about the advantages of the last generation of muscle cars.
Loved my three Gen IIIs, but I am in lust and severe infatuation with my Gen IV -- by far the best Snake I have ever owned.