Like anything you find on the internet, you should err on the side of caution. For instance, IMHO, I would not include the Airstreams of today as well-built, high-end, justifiable high-priced TTs. If you're interested in spending that type of money on a TT, there are better options. I don't mean to bash Airstream per se, but much of its image is based on branding/marketing efforts and some of that hype gets dispersed on the internet.
To answer you question, however, I view Jayco as an upper, mid-ranged RV company that offers a good quality product for the money. At the risk of sounding as a Jayco insider, Jayco was awarded the Quality Circle DSI Award for the seventh consecutive year by the Recreation Vehicle Dealers Association (RVDA). According to a press release, the awards were received for several of the company’s towable and motorized brands, including Eagle Premier, Eagle HT, Jay Feather, Jay Flight, Jay Flight Swift, Jay Flight Swift SLX, Jay Flight DST, Jay Flight Bungalow, Pinnacle and White Hawk. The annual RVDA Quality Circle award is presented each year to RV manufacturers who achieve top scores in dealer surveys in the areas of product design and quality, sales support, warranty/parts support and communication. Source: http://www.rvbusiness.com/tag/jayco-inc/
Jayco has been in business for 40+ years and during that time, other quality RV manufacturers have faced bankruptcy (eg. Sunline). RV manufacturers face difficult design decisions -- everything from creature comforts to pricing to towing capabilities (ie, you'll sell more units if lightweight b/c there are more 1/2 tons on the road than 3/4 or diesels). Jayco and other RV manufacturers have been known to shave a penny a hundred different ways, but IMHO, Jayco has shaved less pennies than others. This forum and others can give you some good insight into the quality of a TT or a RV.
Finally, it has been my experience that trying to name or find the top-best TT manufacturers is like naming the best tow vehicle. The issue: subjectivity. Some folks prefer to have marble/granite countertops with a simulated fireplace roaring in the background while sipping a mai tai in a leather recliner (not that there's anything wrong with that), where less emphasis may be placed on the on-board devices (to save money). Others just want a dependable/reliable TT/RV that doesn't need to be serviced every other time it's used, especially after you just opened a pabst blue ribbon. I think Jayco has done a good job in this latter category, at least more so than other manufacturers.