The Springdale from Keystone is a family of lower-priced trailers. Probably as good as any in its price class, but you aren't talking top-of-the-line models. The construction will be driven more by low cost targets than high quality and long life. I'm not bad-mouthing the Springdale - just trying to set your expectations. Expect lesser quality upholstery and cabinetry, fairly rough construction behind the visible areas, relatively light duty trailer frame, etc. I know a couple who have one and they get decent service from theirs, but they basically use it for a 2-3 week trip twice a year.
In the Keystone product line-up, the better built models are the Bullet, Premier, Outback & Passport. Naturally, those are all higher priced models.
I just sold a 2008 Springdale that we bought used and had it for 8 years. We used it for a lot of weekends and a few one or two week trips. I never had any problems with it other than a roof leak that I caught before it caused any interior damage.
I'd guess Jeff's experience is fairly common for the Springdale and similar competitors. It's the sort of usage they are designed for and they mostly hold up ok at that. Tires and batteries are common replacement items, often every 3-4 years, but major flaws aren't frequent.
I currently own a 24 foot 2013 Springdale that we bought from the original owners that only used it TWICE in two years; they decided a motor home was more to their style than a trailer. Needless to say, they kept the trailer immaculate (and garaged!), and it was if we had bought it brand new. We basically were a once or twice a year RV vacation couple, so it saw minimal use, until we moved from Oregon to Pennsylvania in 2019 and made our move an RV-ing adventure. We spent 102 days in that trailer, and it performed perfectly the whole time; never an issue. The only repairs it has needed is I replaced the tires before our cross-country trip, and I also replaced the single battery with dual deep cycles. I firmly believe that no matter what trailer/RV you buy, regular maintenance is the key to longevity; just like a car. They may be the low end/economy line of trailers, but if you only use them a limited amount each year or are just starting out, they're not as bad as others may lead you to believe.