Reading another popular thread here on board length you would be excused, for being totally confused if you're an average paddler like me.
I am no race expert, I paddle a bit (once to twice a week) and whenever I do, I do it for fun and fitness. I almost always paddle in the ocean and if I race the only thing I hope to beat is my mate and maybe my PB.
With this in mind, I would just like to put my experiences out there for the hundreds of crew who I know will read these threads, get confused, not comment and probably come to the conclusion that choosing a longer board is just waaay to confusing.
Here are some observations after many years of paddling around on just about anything that floats and discovering that longer boards are
HEAPS FUN!WIDER can be faster!Why? Staying on your board and keeping your stroke technique up right till the end is key.
Most paddling and racing for that matter is done in less than average conditions and the ability to stay on your board, relaxed and not weary is the key to speed and enjoyment.
What ever gains there are in shaving inches of the width of a board are completely lost if you end up swimming or get jelly legs.
Jelly legs? This hits most of us about 30 mins into a paddle when its windy and choppy and even a 30" wide board suddenly feels like a tooth pick to stand on.
LONGER is faster, especially if you are in the 100k club.
Unless you are training in the gym, forget strength to weight ratio's. Most of us are not optimal body weight with strength to match.

My experience is that if you want to go faster go longer. Longer boards tend to stay on runners longer with less effort.
Sure, a longer board takes more effort to get going but once its up and running it has more momentum.
There are plenty of fast 12'6's out there but if you go up against a 14' and you dont train, you are likely to get smoked.
By all means go narrow (on paper, narrower is faster) but just make sure you can stay on the dam thing rather than swim. Swimming is def slower.
Dont forget the FUN factor.
Even if you do race, you will be spending most of your time just paddling and around (aka: training) for fitness and fun.
So make sure you choose the board that you can have the most fun on. That way you will train more often and have more fun doing it!
Your weight and ability are key factors in choosing the right board and 'Nine times out of ten' the best board for you will not be what the Race enthusiasts are recommending.
At 92kg I can go either way and I do have the luxury of choice.
When I do choose, it is for these reasons-
12'6 - playfullness and convenience. If I want to catch waves and ride them its 12'6 all the way!
14' - speed and glide. If its down winders and glide I am after (staying on runners). I go the 14'. Nothing beats the glide of a longer board IMO

BTW I have some bad news for those who want to go all the way. Apprantly there are very few crew over 75kg winning elite races!
Well there you go, that wipes out half the SUP population right there, so for most of us it really is about participation, fun and staying fit.
Just my thoughts and open to many more
AA