I have noticed some of the Trailer builders offer as an option to go to 72" between Fenders versus standard 80". What would be the advantage of this ? m

Narrower package going down the road. Fenders are under the boat not sticking out past your truck(SRW). The also tend to ride a little rougher due to the narrower track. I prefer the wider with torsion axles myself

About the only real gain in my opinion is that you can park it in a narrow side yard that it might not otherwise fit in.

I was pretty much thinking the same thing guys ... Seems the wider setup would allow for the boat to be lower ..resulting in better handling ... m