I decided to register here after reading a lot of the complaints in this thread. First of all, I'm by far not a GTA conniseur - I never played GTA 3, but I did play Vice City.
As far as the gameplay, the driving took a little while to get used to, but I'm able to handle most corners with ease. It is how you use the handbrake and the regular brake in combination. In order to take a 90 degree turn at a high rate of speed, you hit the handbrake, and as soon as you start to skid you have to let go of the handbrake and immediately hit the regular brake while not turning the wheels after the initial turn/handbrake. I usually will hold both the regular brake and the gas down at that point, so as soon as I get the car around the corner and release the regular brake, the engine is gunning and gets me going.
Driving in the game is also very dependant on the car you are driving. If you tend to hit objects, cars, etc a lot, then you need to drive a SUV or truck. In SUVs and trucks, and larger vehicles, you can hit vehicles/objects and be hit and will not be spun around as easily (especially at high speeds) as in a smaller vehicle. The calvalcade, once you learn to handle it, is a great vehicle. It handles well, has a nice top speed, acceleration is kinda slow, but you can smash into most objects head on or slightly sideways and not get spun all over the place.
So, if you are having problems driving, experiment with using the handbrake and regular brake in combination. Also, learn how different vehicles handle in the game, they all have distinct properties that make them different than pretty much every other vehicle you can use. I personally prefer the Cavalcade as my general use vehicle.
As for darkness, I can't comment. I'm running GTA4 on a PS3, connected to a 52' 1080P HD TV via HDMI. I haven't noticed any problems with darkness, the game looks incredible.
Also, I'm really enjoying the storyline and the twists and turns it takes. I haven't come close to beating the game yet, but I've been enjoying it very much. All in all, I recommend purchasing GTA4 if you have a Xbox360 or PS3.