Well ... I for one am pretty happy with the design quality and workmanship quality of our 2005 Itasca ... and I've been all over on top of it, inside it, and under it. I've had to tweak some minor stuff, but there's no junky construction in it by any means. Even the design is "quality" in that things were planned and put together with camping safety, comfort, and convenience in mind.
That being said, I'm not sure about any PREDICTABLE CONSISTENCY with respect to Winnebago quality. What we wound up with in our particular RV was probably just plain luck for that year of construction, or that month of construction, or that week of production.
My personal defnition of quality can apply to a new $60,000 RV or a new $600,000 RV: I prefer to get what I paid for to be well executed and remain so over time - less money should just mean less features and/or bling - not less well put together. This applies pretty much to our luck-out Itasca motorhome ... it's plain and simple ... but IMHO well executed.
I use the above definition of quality as a guide as best I can in everything I buy.