Yes, the Fiocchi 'action-proving dummies' are well-made. Compared to the A-Zoom and the ST Action products, the Fiocchi 'action-proving dummies' are much more realistic. The A-Zoom is plenty durable, but they're heavy and they leave behind an abrasive aluminum residue. The ST Action 12g dummies don't leave any abrasive residue, but they're too light in weight and - because they're hollow, with an open end - they don't feed as well as the other brands. The Fiocchi 'action-proving dummies' are made just like a live shell, so they feel and they feed just like a live shell. And, just just like a live shell, handling and repeated feeding will wear it out and necessitate replacement.
Of those, only the A-Zoom is really a 'snap cap', however. Only the A-Zoom will cushion a firing pin. If what you want is a 'snap cap', you don't want the ST Action or the Fiocchi.