I believe *'Vegas Vacation'* is a satisfactory addition to the series. It has its ups and downs—there are stretches that don’t hold attention, but overall it proved to be acceptable entertainment. The Vegas backdrop and the resulting chaos make it bearable, and the scenes involving the dam are quite good. Chevy Chase and Beverly D'Angelo return, along with Randy Quaid. I still don’t find his character particularly appealing; he’s rather irritating, and not in a humorous way—it’s strange to have someone even more foolish than Clark, since Chase’s character is meant to be the primary source of idiocy. The final, more emotional moments didn't entirely work for me, at least in how they were presented. It seemed like it was trying too hard to emphasize family and affection, but that isn't really what these movies are about. The Griswolds are a dysfunctional bunch; they’re not meant to be endearing or easy to identify with. Despite all this, it turned out better than I anticipated, particularly considering the absence of the National Lampoon branding and the eight-year wait since the last film.

Source on TMDB