Looks great, but where's the fun gone?
First things first; this is a port from console to PC and it is not a good one. If you remember the awful port of Halo to PC then think along the same lines. On PC you can remove the motion blur which comes as standard on consoles however doing this really only makes the game look worse. This game is an interesting dichotomy as it varies between looking amazing and looking frankly awful. Also there is little attempt by Rockstar to rectify the game's problems with one interesting update in particular having the interesting side effect of preventing my computer connecting to the internet.
Rockstar also took the interesting decision of reacting to the criticism of the rpg elements in GTA:SA by deciding they needed to be shoved in your face in this game. You are provided with a mobile phone in this game on which you will be constantly bothered by people asking if you want to do minigames such as pool or even going to watch a show. I have real friends that I can go bowling or drinking with, wasting my time driving across the city in GTAIV to then waste my time on a mini-game is not in the least attractive to me, but is necessary if you want benefits such as leaving hospital with all your weapons.
One of the interesting improvements in this game though is the character. Unlike CJ or Tommy Vercetti, Niko has a fleshed out backstory which provides motivation for everything that he does. The actual storyline missions are interesting as they develop this further. However as is the trend in recent games, you will often be faced by a moral decision, usually whether to execute a character or not. I'm not sure why recent games such as Bioshock and Mass Effect 2 bother with these choices when they're so laughably transparent, with one option to be saintly and the other pure evil. Regardless your decision makes barely any difference in this game.
But for me the real problem with this game is the so called realism. GTA3 was a revolution as it brought the series to 3D, GTA:VC was great as the missions echoed great moments from film and tv and GTA:SA is still my favourite of the series, simply because the missions were ridiculous and it at least made it seem as though Rockstar had a sense of humour. The missions here range from chasing people in cars to shooting people on foot. Stealing a jet pack, torching a guy's drug farm; expect none of this in this game. There has been some attempt to spice things up with a GOW style cover system, but as in every game to attempt this since GOW it doesn't really work.
Unfortunately I just found this game boring. There is one aspect of this game which sums up the whole: toll booths. One particular bridge in the game, which you will have to cross many times, has a toll booth on it. You either have the choice of slowing down and passing through a queue of traffic in order to pay the fee or blasting through it with the immediate penalty of the police chasing you (which can be a real pain on some missions). I play video games for escapism and for me this game was just too much rooted in boring reality.