I had one of those Craftsman lights for a long time. It worked just fine. Then I got seduced by digital timing lights, and bought an Actron cp7529, in part because of recommendations on this board. It worked great, lots of fun because you can set the timing you want, line up the marks, and everything is right.
Then, for some reason, a piece of powdered iron (or ferrite?) cracked and fell out of the clip that goes over the spark plug wire, and it wouldn't work after that--no surprise. So, I epoxied the piece back into place, keeping it as tight together as possible, and I hope now it will work--but I haven't tried it yet.
Meanwhile, I sold my old timing light on ebay. Sigh.
There's something to be said for simplicity...