Wanted to add my 2 cents to all the reviews of these. They really are a good buy for the money. The old one I carried had a strong release spring even after getting a fair amount of use for a couple of years. I mostly used it for opening boxes at work and other light duty apps. I didn't carry it for self defense or for anything heavy duty.
Eventually, I lost it. Not the end of the world - I got my money's worth out of it. The finish on the tip of the blade was long gone and the handle had bare spots too. But it fit my hand and I never had a problem with the grip. I got to the point of being able to pull it out, fire it open, close it with 1 hand, and return it to my pocket almost without thinking about it.
I pulled a new from my inventory to use as my new work knife. There aren't any changes from the old one that I can find. The spring seems just as strong. I'll let you know in a few months how it works.