I'm 6'2 and 100kg. The hardcore was my first paddle so I really didn't know anything different. I find it was nice and easy to paddle with but you could also dig in and get a lot of drive out of it when you want to accelerate. Another good thing is that the shaft flexes a fair bit without losing power when you are using it to surf. My wife has the stealth and the couple of times I used it that it really didn't give me the acceleration that I wanted.
My wife has the stealth and she wants to use the hardcore to paddle as she finds it has much better acceleration (she's a light-weight and not much upper body strength). She thinks the bigger paddle gives her more return for the same effort.
I knew that there was a reason she bought me a naish carbon/kevlar SDS - she had her eyes on the hardcore

The coreban is well made also - it took a heap of learners bumps and bangs off the board without any chipping or scratching.
Good luck with the new paddle and I think if you go with the hardcore you wont be dissapointed - oh i measured my hardcore and it is 9.25"