i have them all and they all work so i guess anecdotal evidence won't help much... this is really a sover question; perhaps even a
soverization question (in case you didn't know, soverization is a long and arduous mystery rite, which involves dipping an F2 head in various concoctions while whispering incantations in babylonian, all to bestow immortality on the said head). mr. wong, where art thou, when the faithful need you? speak out!
i hike a lot and the plain prism goes a long way to make the F2 a better hiking prop: it fears water less, it doesn't mind bumps and dust so much, it's a bit lighter (with the F2 this really means "a bit less heavy"), it has a more reasonable form factor..
DP-3 and DP-12 are great, reliable heads, but i find them quite annoying when on the move: the eyepiece shutter has a nasty way of closing halfway when you slip it into the pocket, the protruding EE parapet catches on zippers, the LEDs are near invisible in bright light... i find i end up using these two for a specific purpose--low-light shooting in the city--or at least indoors. the DP-11 is a much more usable all-rounder, albeit the needle can get somewhat jumpy from both under- and overuse over the decades
considering that you can get five pristine FMs for the price of one DP-12 head, i have to agree this would be my preferred route. i also have an FM2N here, which i keep precisely for this purpose. it does feel flimsy after handling an F2, but it isn't too much so, mine took a tumble on mean hard rocks more than once, coughed, cleared, spat, and rejoined the battle, fourteen years and counting
endnotes
http://soverf2repair.webs.com/