ORIGINAL: Venthos
If you check Charger forums and such you can see that there are a lot of people who were on the fence about R/T and SRT8, got the R/T, and later decided they HAD to have the SRT8 and were still upside down on their loan. The R/T is NOT a bad car, but it is neither an SRT8. You need to decide for yourself what you really want and can really afford.
Keep in mind though that was before the 5.7L got a power boost from 340 horsepower to 375 horsepower.
A cold air intake, better breathing exhaust, and a good software tune should easily boost the 5.7L above the 400 horsepower threshold.