sorry if this has been discussed before, but does anybody have theories as to why getting "horsemanned" by apocalypse seems to affect different mutants differently? 
 
archangel: the first x-man/apocalypse horseman. has never been the same since, both physically (blue skin, techno-organic wings) and mentally (in recent x-force issues he started reverting to full "survival of the fittest" mode and could barely hold back killing his teammates!). 
caliban: don't know enough about him to comment and before/after effects. 
hulk: wasn't he war for a while? seems to have had no lasting effects on him, but then again he is the hulk. 
sunfire: got a new pair of legs, then totally lost himself. he's a straight-up marauder now and seems pretty far from redemption. 
gambit: i guess the common theory is that he purposely underwent the horseman process to keep tabs on apocalypse? was this predicted in destiny's diaries? anyway, as we just saw in hellbound #3, remy doesn't have a very good grip on his death persona. (and does anyone know what his enhanced powers are as death?) but he can apparently "convert" others into death as well... 
wolverine: seems to have no lasting effects from his stint as death, despite the fact that he got a brand new adamantium job. maybe his healing factor has something to do with it? 
lorna: how random was her becoming pestilence? but she seems to be perfectly fine post-apocalypse. 
scott: now this to me is the most interesting case...scott was actually the vessel of apocalypse himself! some could argue that the process was never consummated - but still, as ozymandias conclues at the end of "search for cyclops": "can one come so close to darkness...and remain pure?" yet cyke doesn't seem to have had any kind of "apocalypse infection." indeed, even in blood of apocalypse neither cyclops nor apocalypse acknowledged the whole ordeal. 
 
initially i thought that the extent of apocalypse's influence over his horseman has to do with the extent that he "modified" them (e.g. archangel's wings, sunfire's legs). but gambit got nothing but black skin and he struggles with the death persona. and wolverine got re-adamantiumed, but maybe his healing factor protects his mind? 
 
or maybe this is all just due to standard continuity-inconsistency and multiple writers.

The simplest (and most realistic) reason is the change in writers.  Stories & continuity is pretty inconsistent when it's passed from one writer to another.

However, if I were to hazard an 'in continuity' guess, then I'd say it might have something to do with the unique genetic make-up of each different mutant.  So, as you say, Wolverine's healing factor might provide added protection throughout the years.  Angel's own unique healing helped him until it was pushed too far to it's limit & therefore caused the new flip to his powers (back forth between feathers & metal).  But that's just a guess.

i also find it interesting that sinister never seemed to have fallen under apocalypse's control. he essentially took the gifts - immortality and whatever other ill-defined powers sinister has - and then skipped town.