I didn't read most of the OP, I will later, but now I've got some other things to do.
Anyway, me? I liked FC3. I friggin LOVED IT. It's got its issues, sure, but I kind of liked the story (despite its obvious dumb moments), I LOVED the cutscenes (some powerful directing there), and I FRIGGIN LOVED THE SHIT OUT OF GAMEPLAY!
Visceral, powerful, dynamic... I mean, if you make it so. You can camp on a ledge and snipe out the whole camp, even on hardest difficulty, relatively no problem. You can also be totally stealthy and shit and kill everyone without anyone ever noticing. Or you can run in there, guns blazing. But if you do, that's your problem.
What I LOVED, and gave me a huge adrenaline rush comparable probably only to Dishonored's Back alley brawl 30 minutes into the last round, is equipping a *non silenced* (very important) Colt 1911 (my sweet Pinky pie... <3 because what can be more embarrassing that getting killed by a pink Colt 1911 while you're wielding an AK47?), and going in there with an "invisible terror" approach. Shoot someone first, to cause everyone get alerted, and then sprint and slide around, trying to be hidden from sight (just letting them hear me) right up until second before I kill the next one of them, gutting them with machette, or shooting them. Listening to their scared and confused shouts as they hear me there, and few seconds somewhere completely different, all around them, making them hear the screams of the next guy I killed before he could even react to me popping above him, behind him, in front of him, beside him, other than screaming "OH SHIT!".
For bonus points, don't tag anyone in the camp and don't disable alarms, and dispose of everyone before reinforcements arrive, offcourse.
BEST.
FEELING.
OF.
THIS.
KIND.
I.
EVER.
HAD.
IN.
A.
GAME...
...so far.
The sad thing is, throught the first playthrough you don't realize that by playing organically (using fast travel sparingly, liberating camps as you come across them) you make the game gradually easier (less pirate patrols on the roads), and you reduce the number of playgrounds (camps) for the time when you'll have the widest array of moves at your disposal, effectively leading to a situation where the more power you have, the less opportunity you've got to enjoy it.
So, second time around, I liberated the lowest minimum of hand-picked camps so I didn't have to travel 15 minutes to each story mission, was doing only the story missions and occasional road patrol XP farming, leaving all the awesome camp-action for the time after finishing the story, the time when I had the most toys to play with.
And yes, the aforementioned strange situation with "the more you progress, the less there is to do despite you having more tools to do it with, ergo the further in the game you are, the easier and less enjoyable it gets" is one of my main gripes with it.
Also, I played it on PC, but with an Xbox controller, because I fell in love with the thing, how it forces me to be all tactical (in any game) compared to when playing with mouse+keyboard, because it's less precise, so I cannot rely on my superhuman twitch reflexes and instincts (trained up in Unreal Tournament 1 when I was 12-17). It basically limits my abilities in a rather interesting way, making me feel more like a "realistic superhuman" (oxymoron, i know) without the game itself needing to limit me to an annoying degree to achieve this.
I tried playing FC3 with mouse and keyboard once, for about half an hour, after finishing it with controller, and it was annoying. First of all, it didn't feel so visceral (say what you want, but rumble function is GREAT for this, if used properly), and as I said, it turned it into a shooting gallery with almost no need for tactics.
FC4?
Interested. Hyped/stoked? Nope. If it's going to stay largely similar to FC3, and just iterate on the gameplay a bit, I'm okay with that, I welcome the same mechanics in a different setting, I've started growing weary of the tropical island, though I still fire it up once in a while to enjoy terror-liberating a camp or two with my Pink Sweety.
P.S.
First time I was very tempted to kill my friends on the end, just because I was afraid that letting them live really will make the game end and ship me off the island, but then I thought "oh what the hell, there's not much to do anymore anyway in this save, and I'll thoroughly enjoy going through it whole again immediately.", which is the main (non-roleplay) reason I let them live.
P.P.S.
Playing the hallucination parts (or the weed burning mission) while high as a kite = complete and utter awesomeness, which leads me to the other big gripe I've got with the game - it should have a mission replay system similar to Assassin's Creed. I know it doesn't make sense in it within its world, but having to savescum to keep saves before these parts, and having to replay the game to be able to store those saves away, a bit annoying...