It is indeed a useful tool. As doverham pointed out in a previous thread, they do not give quite the maximum "spread" that you can get with a hand load and the Polywad post/disc arrangement, but they are relatively inexpensive and seem to be very consistent to me. Again, of importance to me is the recoil ...... not how little or how much, but the fact that they feel almost identical to my regular loads. I could match that with a hand load, but it would take some time and experimentation.
Why is that important to me? So much of this game is mental. I have to remain in a completely relaxed state of mind to shoot my best, and keep my thoughts as free of extraneous things as possible. That's the exact reason I shoot two modified chokes, and don't use screw-ins so that I'm not tempted to change chokes for different presentations. I see I've got a very close rabbit, or bird, maybe it's a windy day and the close bird is taking unexpected nose dives ....... I drop the spreader in the appropriate barrel, and forget about it. Quick and easy. If it is the first bird, the recoil is exactly the same as my other shells and my mind is not drawn to that for a split second when I should be picking up the other bird with my eyes and then moving the gun to intercept it.
Am I anal about it? Probably! But, it's working!!
SRH