Re: Fairing Compounds, what do "you" use?
Microspheres and cab-o-sil in about a 2:1 ratio with your favorite epoxy. The cab-o-sil (fumed silica) is the thickener and makes the epoxy very hard (nearly as hard as neat epoxy) if used alone. The microspheres make it sandable but makes the epoxy weak in too large a ratio. For large fairing jobs you can increase the spheres to ease sanding.
I used this method to fair a very bumpy Cal 25, my San Juan 34 after a complete blister peel and several other smaller projects.
I've used West's 407 and 410 fillers with good results on small projects but they are very pricey.
I buy my fairing supplies from Aero-Marine for less than I can at WM even with my Port Supply discount.