Composites ain't for everybody. But in my case I'd definitely do it again. And I will with the C-500. She's a lot less complicated than a 153. Transom, keel stringer & floor. That's all there is to it.
Don't forget you can shape the stuff with a razor knife, file, & a piece of sandpaper. Plus it'll never absorb water, ever. It don't care if you drill a hole through it or drive a screw into it. Resin sticks to it like flypaper. Factor in the weight savings, doubt the 153 was much over 450lbs dry.
Those who's mantra is "It lasted 40 years with wood so why use anything else?" are beginning to sound like a broken record. Yeah it'll work just fine I reckon. But why not take advantage of the latest technology? In the long run it ain't all that much more expensive.
Well, less'n ya smash it into a channel marker afterward ... But I will tell you this: That stringer/floor system was so rigid that the only place the floor delaminated was on the opposite side of the boat from the point of impact!?
I think you're doing yourself a disservice if you don't at least consider using the stuff during a rebuild.