Ok, so i tried the punisher with heavy bolters today against daemons. And by God it is awesome. It destroyed two 15 bloodletter units. Or the majority of them.
It simply just mowed them down. It definitely gets more hits than pie plates. I had two medusas in the list as well, and they were awesome too! Didnt do as many wounds as the punisher, but it really helped thining out a 20 plaguebearer unit.
I also tried the bastion breacher shells against a leman russ heavy and mech inf list.
They are superb anti tank! They cut through anything! And if lucky then you hit fairly well. The only downside is their opentop-ness and their inability to fire indirect so they have to engage in firefights with their targets.