Rocky is dead on, on all counts.
I'm old enough to have used a bunch of the old lathe turned Partitions. They aren't quite as accurate as the new design, in my rifles.....but, we're talking 1.5 inch groups for the old stuff, and smaller groups- as good as any other non match bullet- for the new stuff.
You will sometimes find, as Rocky said, a regular sized exit wound on a deer, if the partition has penetrated a lot, like on a quartering shot. You will find the exit wound rather easily- look on the ground right close to where the deer was when you shot
IMO, the secret of the Partition's success is , in part, that soft front- it always expands. Always. Always.
And the rear, partitioned off section always keeps going.
I've only recovered one Partition bullet from a deer. And that was after 33+ inches of penetration. The bullet destroyed a shoulder joint, too. The recovered bullet looked like the perfect ones you see in the ads.....