(PS3 version)
I've completed one playthrough of the game here and I must have played a different game from some of the reviewers. Sure, the technical aspects aren't great and the gameplay isn't as good as what you'd find in proper shooters (go figure, because it's not strictly a shooter game etc.). And yeah, the AI isn't that great. However, I honestly haven't ran into many bugs apart from one or two graphical glitches during the talks with Leland. The only other glitch I encountered was during a mansion level in Rome (I won't mention more). When I backtracked through a door, the whole screen goes black and such.
Anyways, as long as you're willing to look past what was mentioned and buy it for the rpg elements (i.e. the choices and how you can influence the story and such), you really should enjoy it. That's where the replayability comes into it like Michaellung said. Like, if you choose to help a faction out or gain their trust, they may help you out on missions and scenes may not be seen depending on what you do. Also, the order in which you play the different hubs/missions has a hand in determining how the story pans out. (Note: Not the overall story arc, but the little things and allegiances etc.)
Edit: By the way, I'd recommend playing on normal first time out and probably not as a recruit so that the game's not difficult. I've not tried it on hard yet so I can't vouch for how difficult it is, but I imagine people in the streams had problems because they went on the hard difficulty and chose the recruit option. Either that or they just weren't very good players and didn't play how they were meant to (i.e. avoid setting off alarms and take enemies out quietly when they can).
By the way Flintlock, the review scores basically just shattered the small amount of trust I have in reviews. Thankfully, I always read about games before buying them, so I rarely end up making a mistake. Sadly enough, based on the live feeds and all of the complaining, I did nearly cancel my pre-order of the game. Thankfully I didn't.
I feel bad for Obsidian mainly due to the bad press because it's not as bad as what people make out.

GOD DAMN I HATE BRAYKO HOW DO I KILL THIS FUCKING ASSHOLE
I played Taipei first, then Rome, then Moscow. God freaking damn it. Mostly using AR, I have a bunch of those perk thingies (I guess that's what it's called) like Fury and whatnot and they suck ass. Maybe next time I shouldn't use up my health packs so early on in the game.

So it looks like there's fake AA in this game, even on the PC version? Can it even be turned off?
Unreal Engine 3 sucks so much.

I rarely trust reviews either. For instance, the Saints Row series, too many revies started crying "HEH BAD GTA CLONE, IT SUXS".
In my mind, so what, they didn't attack a lot of FPS's as being clones, and besides, what about judging the games on their own merits. I'll use them as guides perhaps if its giving game info like how buggy it might be, but when it comes to the gameplay itself, I'll make my own mind up thank you.

When he goes nuts, don't try to attack him, just run. He gets tired after a while (you'll hear it) and you can get back to shooting him
The boss fights are about the only thing I don't like about the game, for a game about choice the fact that most of the bosses are vulnerable to just one trick seems odd. I'm currently stuck at a boss fight right near the end of the game with a guy who can throw 3 grenades at once and has apparently got infinite troops (that or I've just not killed enough yet)

Like I said, freakishly weird but it seems to work
Really?? Awesome, going to do that next time. Heck is well worth playing along with, amusing nutter
Walking a LOT more in Mass Effect and often taking rides in the lift to accomplish the same job.
Weird thing is that I've been playing Borderlands on the 360 as my second game when not playing AP and the texture pop in is actually a lot worse than AP's

So as a gamer who doesn't care about graphics and special effects crap, and only about whether the story is immersive and if the gameplay is diverse and fun, would you advise me to get the game?
I'm more or less set to buy it in the retail store.

I've finished the game now, I thought it was good. The ending that I got was nice as well.
If someone is like, interested in the game. I would recommend playing it as a freelancer so you can put out your own points. Gun + Assault rifle. (With the gun you can do 10 headshots in one moment. Enough to kill any boss. Must have brilliance though.)
And martial arts and stealth. About hacking, just buy some gloves for it.
It will make it a lot easier. Just put two points to sabotage and you're set.
Also use EMP so you don't have to hack in important moments with lots of enemies around.

I would say yes, I got sucked into it and then noticed it was half 4 in the morning and that doesn't happen with many games

how does the game perform on your hardware?
i got amd 3200, 4850 and 2GB of ram.
Empire, Fallout 3, ME1, Mirror's Edge and Bats:AA work flawlessly on med to high.
they are all at least year older than AP. will it work alright on my specs

If ME1 and Arkham Asylum will run, this will as well.

All backgrounds can be customised--you can delete the defaults.

I will wait for price cut on this and buy it retail because game's reviews are not so good and there is no demo to try. I love Obsidian's games but I don't think SEGA will support this product and allow (fund) Obsidian to make patches.

I'd say yes. I don't know what it's like on other platforms outside of the PS3 though.
Also, as Skarai said, I also played as a freelancer, so I'd recommend that too.

Thanks I already got it, the retail version. PC of course.

Pros
-Good soundtrack
-Good dialogue + voices. Thought the dialogue worked very well.
(Works well to take another choice then to just go with one stance all the time)
-I like the characters, didn't find anyone of them to be 'flat'
-I liked the ending. Got real choice and none of the Good vs Evil
Cons
-The animation are average, it cuts between so it isn't fluent
-Some bugs and glitches
-Boss fights are, as usual, pretty annoying. But you can them down pretty easily depending what build you have
-The shotgun is very weak
-The submachine guns isn't all that useful I think. I mean, so close you might as well use melee. Which works better. But I only tried them once. It's more of an observation how the enemy used it and how effective it was against me. (It wasn't)
That is all. Oh, this also.
If you can't see the dialogue, you need to enable AA and AF through graphics settings.
Just set it to application enabled. And it will work.