I really like the E-tip. Here's one that I recovered after shooting it head on into a mule deer's chest last year. It traveled nearly 3 feet through the deer and ended up just inside the hide before it entered the hindquarter.
99% weight retention and it petals out perfectly if it doesn't hit bone. The petals are much stronger than you woud think, you can't bend it short of putting it in a vice and using a pliers (or hitting bone at 3,000+ fps, this bullet was shot out of a 7mm Rem Mag at approx 50 yards).
It ended up with 2 petals extended and 2 folded back so it probably tumbled while it was going through the deer. I didn't open up the chest cavity (I use the gutless method), but I would bet everything inside him was torn up pretty good.