I'm an ex Herc mate and will defend that aircraft to the hilt, however it would make a fairly mediocre MPA for the UK, given the size of the sea space that must be patrolled.
I was in a headquarters role on Joint Warrior a while back and got chatting to a Danish submariner with a lot of time on their diesel-electric boats. The only MPA that they feared was the Nimrod as it was the only platform that had both the radar and speed combo to get a hit off their mast and dash into their location and put out an effective sonobouy pattern to lock them down before they went deep and silent and poked off on a random track. Atlantiques and P3s just didn't have the smash.
I flabbered his gasp when I told him that we'd scrapped them and their replacement.
The UK needs a 21st century jet MPA. That'll be a straight competition between the P8 and P1 (which I'm rather partial to).