Has to be a lot better than the old junk I had--it would take a swing from John Henry to even get close to activating them. Looks like you got your money's worth! I realize, however, that you're not recommending that someone looking for a new impact driver should seek one of these 1970s Talcos out.
One of the nice features to the Koken is that you don't have to pound it so hard to get the cam to engage. In fact, Koken tells you NOT to smash theirs with a heavy mallet because you don't have to. You can place this Koken stud against the edge of the work bench, give it a firm push, and the drive will immediately engage the cam with moving in only a very short distance. The old ones I have would not even budge like that using all my strength to push, and would just laugh at me.
It's impressive that the striking end on your Talco is so mushroomed--it would take some heavy walloping to get it that way. I can see that kind of mushrooming with heavy auto/machinery work. You must be a strong fellow, and I admire that--I'm not, especially at my age. If you can find one that doesn't require such pounding, why not? If you're trying to free a stuck screw at the corner of an old cast-body carburetor flange, for example, you might well bust it right off with a 'brute' driver. I'd probably break stuff working on a push mower like that too. I sometimes need to work on other things with stuck fasteners that don't have thousands or even 100s of pounds of steel to power-pound against.