Hi Steven,
I'm 6.2 and also slim and have been paddling about 18mths ( newbie) and have recently upgraded to the kevlar Think Legend from a fenn XT and cant tell you how glad I am I did...it's fast and yet (for me) was stable enough that I didn't find the transition from the stable XT too much..it just loves the bumps and jumps on most runs with eagerness...I have yet to take it out into some big stuff but believe its there that it really excels.
Thats my novice view, perhaps some of the guys who have been paddling longer on the Legend might be able to give you their views as well.
Best of luck with the decision
Alex
;D