I have now tried all three on my current go-to axe, a rather responsive Collings MF5, so
here's my 2˘ worth:

(The MF5 and) I prefer the D'Addario over the Martin, but the Mangan takes the gold, so to speak.
The Martins feel more taught when stringing up after removing the old Mangans, which is the opposite of my experience: A new set usually feels noticeably lighter and springy when strung up to tension.

The Mangan strings even from break-in to removal feel more flexible, due to lower tension, possibly. The windings seem closer and tighter, giving them a slick feel with less finger squeak.

The D'Addario fall somewhere in the middle, without the odd buzz that the Martin's 'D' course produced.

Martin are cheapest, Mangan least cheapest placing D'Addario in the middle, but really very close to Mangan and Martin at closer to half the price.

Individual results will likely vary.