Finished the story, got 100%.
Grand Theft Auto IV/Story Walkthrough - GameWiki
I like it, but compared to San Andreas it is weak in the content area. It has a nice look and feel, but it disappoints in the world. The goal as I heard was to make it more believable and more compelling, but they reached that only half way. The graphics looks it, but the game itself failed miserably. You get to hear about large figures in the game but never meet them. You hear about events and places, or see places, but you never get there or be able to experience something with them. Places like the airport and the train station are solid blobs, not enter able, while some apartments high rises can be climbed stair by stair all 40 stories high. What's even more frustrating is that there are cluckin bell and burger shots all over the city that you can't enter. Some you can, others you can't. You only have 3 weapon shops all over, 5 pay and sprays, and you get 3 safe houses (a fourth if you decide to kill one and not the other person, close to another safe house you will already have). You can't buy many clothes, and changing them is terrible. You cant change your car, other than random paint it at a pay and spray. You can't buy any properties, safe houses or businesses like in VC or San Andreas. The weapons and armor is hidden everywhere, but REALLY hidden so you would not even stumble upon it by accident in 99% of the cases, in short they are useless. You can spend you money on a few clothes, some mobilephone upgrades (ringtones and that stuff) and weapons, thats it. You can buy food and pay a cab.
I am looking forward to the episodic content and the next GTA too, because THIS game here, I rank in GTA terms below Vice City. It looks a hell lot better, but the game itself is disappointing to me. And yes, I have played both to 100%, even wrote a 100% guide for San Andreas.