Haven't used Pro-Set.  West System's Six-10 (CLC sells) comes in a cartridge.  It takes six to eight cartridges to complete the fillets under the kneeling platform of a Cocktail Class hull.  Saves time but is pricey at over $20 per cartridge.

West's 610 comes in a single cartridge that fits an ordinary caulking gun. It is a slightly toughened (non-brittle), colloidal silica thickened mix, and uses disposable mixing nozzles. It's a great product for repairs away from the shop since it requires none of the usual list of implements- mix cups, stir sticks, containers of resin and thickener, etc.

Pro-Set's cartridges are double barreled jobbies, requiring a special (and expensive) caulking gun. However they offer a broader range of resin choices, aimed at the professional shop.