The E63 gains more from tuning alone due to being turbocharged and with a Renntech tune puts out 621 wheel horsepower and 712 pound-feet of wheel torque on 93 octane. Renntech M157 Twin Turbo 63 AMG cars have run as fast as 10.7@130 in the 1/4 mile with bolt on mods. So, a little bit quicker and faster than RedBullJnky's best of 11.03@126 on 93 octane with full weight. Overall his personal best is 10.73@129 which is right inline with the M157 but the turbos just seem stronger up top.
The video below shows the top end advanatge of the M157 as in the first run with the E55 getting a considerable jump the E63 still runs it down and passes. Later on we see a more even start and the E63 does walk away.
Two strong cars showcasing the difference in bolt on tuning between the previous generation E55 AMG and the newer Twin Turbo E63 AMG. Thanks to @RedBullJnky for the footage.