There is a split between "oude gueuze", brewed to tradition, and "new" gueuze, a variant optimized for widespread palatability and time-to-market. This is a "new" gueuze that I purchased at the local grocer's (in Belgium) because I'm keen on trying every Lambic in Belgium (there aren't that many, so it is a practical goal).
Mort Subite pours a pleasant amber color with a nice frothy head. The beer is quite clear, which is essentially impossible to do with the traditional approach and hence sends off warning signals. The nose has a vinegar-like acidity, with a cider character, and only minimal symptoms of Brettonomyces (these are wild yeasts which give real lambics their characteristic and delightful barnyard aromas). Flavor has an apparent, though one-dimensional acidity, and, like most "new" gueuzes, is corrupted by the sweetness of sugar. But, unlike most "new" gueuzes, the sweetness does not lead to failure here; it actually adds a nice cider/apple character, with similarity to the Rodenbach Gran Cru and is pretty well balanced by the acidity. Ultimately this gives it a realistic and refreshing fruitiness. I don't hate this gueuze, but I will not drink it again.