I LOVE Fed SP primers and prefer them to all others for their superb reliability (I use lightened hammers in several of my guns) but they do have a minor liability- they can crush when pressed into a some tight .380/.38/9mm pockets like an S&B, WW or similar case. With any of the other major cases I have no problems whatsoever. I have no such trouble with S&B .45 cases, but the .380/,38/9mm S&B brass I find is either given away or goes into the recycle bin.
A minor issue, to be sure, but worth mentioning. Otherwise, I HIGHLY recommend Fed SP primers.
edit- I only load mid-range loads, nothing hot.