449/511 Te450 Advice Appreciated

Would like to thank everyone on beforehand for any advice/ help.Your opinions will help me make a decision.
Currently own an 2008 te450 (euro no emmisions stuff etc).It flys and i love it but need something a bit more refined.I am 6ft 3inch and 104kg(229lbs).
Judging by what others say the 449/511 models perhaps are smoother,more refined,better in the tighter stuff and vibrate less but still have that grunt if needed.
It seems the 449/511 would fit the bill.Any comments,advice or disagreement from your experience is most welcome.It will help me make a decision
I dont want to drop 13k on a new bike.I dont race in competitions.Level medium moving slowly towards advanced cross country rider and loving every second!

Thanks Nick