I think the focus of the question was around a ranking of manufacturers:
Aside from high dollar custom conversions the ranking generally comes in at:
Newmar
Tiffin
Winnebago
Forest River
Fleetwood, and Thor rounding out.
Some would argue to slide one above another or vice versa but I think that's about the general consensus. Price reflects what level you will get in a particular brand. Newmar's entry level model will be far more expensive than Thor's for example. Some quality differences as well. But if you want to spend less, generally you get less. Nothing wrong with that on either end of the spectrum provided it's an educated decision. So you might want to go with Tiffin's entry level when you could buy Forest Rivers mid line at the same price. Just know that there will be less bling and more quality.
But a TON of other factors to consider as others have said. Floorplan is more important than brand.
The best place to start any RV search is floorplan. Pick a floorplan and THEN find a brand that has it in a year you are looking for, on a chassis you are looking for in a price point you want to pay. This will start to whittle your choices. Then you will see that ABC's brand of the same floorplan is considerably more or less money and more or less quality than XYZ's.
Again more decisions, maybe you like ABC's quality over XYZ's but can't afford the price. Then you shop for older models. etc etc.
Took me 5 years to finally find a model I wanted in a price I could afford. A year later I bought another floorplan I liked better but wasn't available when I bought my first one. Now another floorplan comes out and looking to trade again. Point is, there is no right answer here and you will get a million opinions on what to buy.
Research, due diligence, experience and mistakes will guide you to your right MH.
2013 ACE 29.2
