You know board size is very much dependent upon the wave (and crowd sometimes, too). So for example, at Point Conception there's a long period wave that rolls in thick and strong. If your board isn't big enough, you have to take off late and steep. If the wave's going to throw, you're not going to make it. You need a bigger board to get in. Waimea is a fine example of this, too. I used an 8'2" there and loved it, but again it depends upon the swell. This last Eddie swell, something like that NEVER would've worked. Mavs is another example of that. You need the long board to get it.
But in a short period event, sometimes a smaller board just works. I always prefer going smaller, but that's just me.
There's also a crowd and bottom contours component to this. Teahupoo will not let you ride a big board easily. Cloudbreak will. But Cloudbreak without a crowd is easy to get into. So... yeah... f me. There's a lot of variables in all of surfing. Cannot wait to take my new asymmetrical board to Cloudbreak. I have a feeling it's going to work well there.