No experience, but I have been lusting over those for a while.
Here's a good question; for the same price why choose Marchesini forged Al over Marvic cast Mg? For street use, is the answer strength and durability over weight savings?
if you like the marvics, i'd say try the piuma's instead of the penta's. had 'em on my s4 before springing for BST's. they're lighter than the penta's and stronger too. amazing wheels (sold mine long ago).