This is nowhere near as good as GTA III
My first impression of GTAIV was "What the f*** they messed up liberty city" Also the controls were weird at first and it was just too dark. I got used to the controls and adjusted the brightness. Then I thought "Wow this is fun" But then as I started to play things just started to get repetative. Missions would give over $5,000 (one mission gives $250,000) but the only things that you can buy are guns, taxis(which can get for free from Ramon), and lap dances; no property. And to me the cellphone is just an annoyance. You have people calling you complaining about how you don't hang out. Why would I want to hang out with some of them if most of the things you get from them aren't very useful.
The physics for the cars are not what I want for a video game. Most cars barely turn and it is just too easy to destroy your headlights, making it hard to see.
Taking cover while it does make missions alot easier, the enemy can also do it. Going on a rampage just isn't fun, you just can't mow down people and there isn't a spot like on top of the old Liberty City's Portland police station where you can kill indiscriminatly and the only way you can die is by helicopters.
Overall the game isn't worth buying just yet. It is an OK game and you can probebly get it for twenty bucks at Christmas. However, if you need a good game to waist endless hours I would suggest Call of Duty IV over GTA IV.