It depends what you mean by "worked better". Yes, they opened up larger. That isn't always a good thing. The bigger the bullet opens up, the less penetration you get.
For example, I shot a deer with Barnes expander 3/4 oz shotgun slugs. The first shot (it was running and already wounded) must have opened big because it took half the guts out the far side. If this would have been a shoulder shot, I would have lost half the meat on the deer, another reason I don't like explosively expanding bullets. The next shot indeed hit the shoulder, and the bullet failed to penetrate into the lungs! The entrance wound was massive yet did not get into the body cavity. I had to chase the deer down and put another round in it later.
SSTs, so far, have never failed to acheive penetration. Unless the shot is long range or frontal, I usually view fail to exit as a bad indication with a ML bullet. I've never had an SST come apart, if they did for you that's not usually good either.
It's personal preference what constitutes a "good bullet" and if you're happier with the results from the Barnes then by all means stick with it. But I don't think the SST is a bad bullet.