I happened to open an old bottle of 1999 Malvasia, and then received a gift of a 2003 Malvasia. The old Mavasia was undrinkable; the bottle says "serve chilled and drink young" and I suggest you take that advice seriously.
The wine is not too terribly sweet, and has a nice sparkle. There isn't much bite (low alcohol) and very little body. My main problem was with the finish; I found the aftertaste of the wine to be disaggreeable, but then again those who enjoy the line of sweet fizzy Bartenura wines had no trouble drinking them. It's better than the Bartenura Moscato d'Asti, which is very faint praise indeed, but even on its own terms it's a decent enough wine for when you need this kind of wine.