USC KROMATE™ LIGHT is a good all around choice for floating out dents etc... West Systems is what you would use to repair a fiberglass HT on a 40, Corvette, TVR or other fiberglass car..or boat. Or if you contemplating not welding new metal in and wanted to glass patch....you wouldn't do that would you ?
West Systems is mucho expensiveo. They are expoxy resins and hardeners. The fiberglass comes into play with either matt, roving or pixie dust. None of the above would I consider an economical or practical way to float out say a dent that you've pulled/hammer/and dollied on. Now West Systems does have quite a variety of other additives you can dump into the epoxy and harderner mix...filling and fairing additives/compounds. These can make life alot easier when working them and sanding them after they've hardened. But again not my first choice for general floating out of dents and dings. Other more typical auto fiberglass/bondo derivatives such as Duraglass or Tiger Hair will require subsequent filling with a light filler to float them out. It all depends what your mission is.
Yes, West Systems is expensive, which is why it wasn't my primary recommendation, Evercoat was. Depends on how serious you want to get.
And note I said I would use the fiberglass based filler on a "good size imperfection" as a base. "Dents and dings" don't require that much build, so it would be pointless to put it down on something that small.
I guess I try to turn good size imperfections into minor imperfections by pulling, hammering and dollying or welding in new steel. Evercoat unless they have different formulations these days always seemed to be rather heavy compared to Kromate Light or Feather light...Does evercoat have some lighter products these days ? I haven't used them in a long time, but the local supplier carries them still.