(Long post, ignor at will)
Yes, like your grandfather I have had Craftsman tools for decades with no problems. I started with a very complete set of open end, box end, and sockets as a gift about 50 years ago. I was a very young lad at the time! Since then I've bought more advanced rachet handles but the original sockets have worked well. I have added to my socket collection, however.
My basic philosophy is to buy good tools, but not the absolute best, at least as defined by the cost criterion. I have no desire to test my tools to the max, so I don't have a clue which are the absolute best, and I don't care to pay to find out. (Maybe the British Car Forum could get a grant from Consumer's Report and launch a research project.)
The money I save is used to buy more specialized wrenches such as short wrenches, long wrenches, thinner wrenches, deep sockets, u-joint sockets and whatever. Since I am not likely to break my tools, even working on British cars, I concentrate on having just the right tool to enable me to get at that stubborn, rusty, hidden nut with a wrench that is least likely to damage the nut and my knuckles.
I like the Craftsman tools also because they have a wide assortment, frequently are on sale, the store is close, the catalogs are convenient, my wife thinks their stuff is cheaper, and the quality is more than adequate for my amateur applications. That takes care of the American and metric tools.
As far as Whitworth tools are concerned, I bought anything I could find on a trip to England several years ago. Some of them are obviously cheapo stuff, but again, none has ever broken. I do take pains not to overload them because they would be a nuisance to replace.
I have bought a few air-powered wrenches, but for some reason I rarely find an application for them. In part it's because I don't want to break a bolt since you never know when you might have to reuse it in a pinch.
A good set of taps and dies in American, metric, and BSW sizes has saved me a lot of time having to locate replacement parts. They're expensive but have been a good investment for me in terms of resurrecting slightly damaged parts.
The bad tools I have bought have come from swap meets and those auto parts stores that are open at 6am on Sunday and midnight on Friday.
I'm glad you asked the question. I've never had a chance to explain my tool-buying philosophy. I've assumed no one cares; maybe they still don't.
Billca