My opinion is the "level" offerings have nothing to do with quality. They have everything to do with option level. It's like saying that a loaded Ford has better quality than a base-level model. Nothing to do with Quality.. Everything to do with trim level.
My personal opinion is that more options - meaning do-dads (not cabinet options) often mean more systems. More systems bring a greater chance of failure. I'm not saying buy a stripped down model, but the more complication you have, the greater the chance of an issue. For instance, search for issues with auto-level systems....
I've been searching for a way to objectively measure quality. The bottom line is that you can't because there are no objective measures or long term road tests. Further skewing things is market volume. So if Keystone generates 10 complaints and Jayco only 2, does that make Jayco better? Not if Keystone sells 500% more RVs... The metrics are not available or transparent.
Here's what I recommend:
1) Read the Texas Lemon law report, google search for "texas lemon law 2015 annual report" - see if the brand you're seeking shows up as a lemon frequently. Search for other years.
2) Read BBB complaints. Not only the number of complaints, but see how the company responds to consumers. Remember, not all consumers are rational, but you can get a lot of information on how a company handles problems from the BBB response.
3) Remember that we don't have market data on number of units out there, so raw complaints doesn't necessarily mean anything.
4) Find the owners forums - see if the company monitors/responds on the forum and see if the forum is open to brand criticism.
5) Consider the length of the warranty
6) Call a dealer in the "national" dealer network out of the blue. Tell them that you need a warranty repair for a leak near the front door. See if they're actually consider the repair or see if they ask "did you buy it here". Not all dealer networks are really national, especially some of the big ones.
7) Will the manufacturer provide direct consumer support? This is a big one.
Largely, most of these are built with the same construction techniques. What tends to vary is how hard it is to get service after the sale and how far the manufacturer will go to support the product after the sale.
Learn how to spot a manufacturer that does care about quality - one that puts real tires on their units, has wet bolt kits standard / optional - basically that isn't about just selling the bling, but is about producing a unit that can move down the road.
I think DRV makes good RVs. I think Grand Design is also very concerned about supporting their customers. Jayco has a 2-year warranty and direct customer support...