SF- Yes, you're right.
But it's not all about length... just flotation.
My 1st two Flashy's were 6'2" and 6'4", and although I loved them, I couldn't catch waves without at least short flippers as easily as I hoped. I figured it was "pilot error" and I just didn't have the paddle power.
However, after I got a couple small wave boards (5'8" PigFish and a 6'0" Chop Tail) that had loads of foam hidden along the stringer, I never wore flippers. (Not like you need flippers for waves under head-high anyway)
After talking to Bruce, my next few boards are the same length (6'2" and 6'5") but they have alot more foam... and I love them! Haven't surfed waves over DOH, but so far so good.
(I always have my shorties with me though... sometimes the crowds/currents/energy level outweighs they performance advantage.

)
Two other things to think about:
- Some boards are shaped with "arm paddle" ability in mind. Their outline makes this possible. Of all the boards I've ridden, it seems Parkes, Islands, and Flashpoints paddle different. They don't want to be "kicked" into waves. They plane better when you are "up on the board".
- Guys who surf without fins hunt waves differently.
Closely watching Gavin and Karl and Jaime and MattyG in Santa Cruz the last few years, those guys sit super deep and watch the wave jack untill the last possible second. A lot of us see a wave and turn and just try to catch it, but those guys are a little more in tune cause they know one foot to the left or right can be the difference.
It's also why Gavin seems faster than everyone else. He is catching the wave at the "perfect" moment every time, and his 1st turn is already Mach10.
KidRock- Baden Smith rides a 6'6" shortboard... and trust me when I say, no one on this thread is half the the surfer he is.