I don't think when you compare Beneteau's and Catalina's there is a appreciable difference in bulid quality. Each has different compromises, so it comes down to which ones carry more weight for you and which boat has the features you desire. They both are targeted to the same market for the same types of use. For me, Catalina's just seem to have an edge in terms of what I like in the layout of a boat.
I usually dream about my next boat being something like a Sabre 387 or 38 or Caliber 35, but knowing my fairly limited sailing ambitions and severely limited budget, I keep the Catalina 42 on my list of boats to dream about, based on its price/availablity, nice lines and spaciousness. (Yeah, Yeah, a pullman isn't as nice as a centerline, but at least you don't have to get out of bed "tail over teakettle" like you do in a V-berth.)