I'm 5'8", weigh about 135 lbs and usually ride a 155 '08 SL. I got a chance to demo a 154 Proto earlier this year and was totally blown away by how much fun it was to ride, such a responsive, poppy and fun board!
Long story short: I'm leaning towards getting a 154 Proto. What do you guys think, does that size sound about right?
Under normal circumstances, I'd recommend a 152 for your weight. However, you already demoed a 154 and loved it. So going with a 152 would be a gamble for you.
If things pan out, you might love the 152. Right now, the question is, do you think you'll love it THAT much more than the 154? Because you see, if you end up disliking the 152, you just lost out on a lot. If you end up liking the 152, it'll more than likely be a small gain over the 154.
I always say stick with what you have demoed. If there was nothing wrong with what you demoed, then you should definitely stick with the 154.