Generally in my experience you'll definately know a good knife from a bad knife just by using it. Most of the "Junk" knives that I wouldn't trust tend to be small SAK knockoffs, and while some are better than others I tend to stick them someplace where they'd be handy but not essential. Plus, when I tend to smack up a knife I'd rather it be a cheepie than a high-dollar gentleman's knife.
The Gerber Winchester looks to be a decent knife from the pictures I've seen. I've had a few Gerber knives in the past, and the only problem I've ever had has been small areas of rust on the ones that I used in a marine environment without much ability for care. I've got a Gator right here beside the computer waiting to be stowed away in my camping gear. My theory on tools is that I'd personally favor having the best I could afford, but I like to have a fairly decent backup that I could lend/borrow/sell without too much of a worry. I can put a knife through a lot worse abuse than it would most likely ever encounter in a fighting capacity, and I'd say that while I wouldn't want to do it on a daily basis the Gerber should hold up to the majority of my demands. If it's working for you, stick with it. Save up some money and try other knives, there's bound to be others out there that you'll like even more than the Gerber. It sounds to me like you've found one that's working for you right now, though, so I'd stay with it while I look. .
