I stand corrected on the winds, however you failed to comment on the 60t of 31 for the PS4002 as compared to 65t of 30 and a shorter stack on the FVII/TSR. Perhaps Dan at Pro Slot can produce a 65t/30G version of the 4002.
Ray, they are completely different motors, as the FK motors have molded neo magnets as well as the other difference you mention.
If Dan made a cheaper motor that was the equivalent of the Puppy Dog, what do you think would happen to the sales of the PD motors? No real incentive to buy the PD, right? And I'm pretty sure you would find the Chinese-made arms would have a much wider range of variation from slowest to fastest, so you would end up buying three times as many motors to get a good one that "hopefully" would last.
At least with the FK motors, the few that are fast get thrown away after a few races, so it's "self limiting"; nobody gets to keep a really good one for very long.