Virtuswarrior

I have a 2014 S550 which I believe is a 4.7 V8 Twin Turbo. I had an accident with this car and it had to be repaired, however fortunately the engine was left unharmed for the most part. Ever since, the car's performance is not the same. Usually when I would put my foot down I could really feel the car push be back into my seat, however now I feel very little pressure at the lower rpm's making my acceleration a lot slower, eventually at higher speeds I feel it regains some power. I'm not sure whether one is working and one is fault OR it's computer settings OR intercooler? Was wondering if you could shed some light on my situation.
P.S Is the twin turbo system Parallel or Sequentially based? Would appreciate all your comments.