So I made the switch this year, took two animals on two shots. Barnes vortex (TTSX) in .308, 168gr. Both died within 30 yards, one shot.
The antelope I shot @ 230yds, the bullet went through both front legs, shattering the humerus on both sides, and took out the aorta in between. I found one fragment while butchering the front quarters, but the edges weren't sharp. I hired someone with a grinder to grind up the shoulder meat, and they didn't find any bullet fragments, nor any copper marks on the grinder parts.
The more interesting thing, is that I lost less than a pound of meat to bloodshot, both shoulders combined, despite what I would call devastating results. Still good for the grinder.
Mule deer was 150 yards, high lung shot, dropped like a rock and never got up- just slid a bit. Never found a fragment.
They work, so I'll stick with them. But I still practice with lead at the range- just find something the same weight, with similar ballistics, and go save some money. Put a round of copper on paper before you go hunt, call it good.