Difference Between Aluminum And Steel Flywheel?

IMO, you shouldn't expect too much.
A steel flywheel car is easier to drive, the hit of the heavier flywheel also helps motivate full weight street cars.
With the lighter flywheel, expect lower speeds and traffic to be a little more of a PITA.
I've had them both, i'll take steel every time.

Aluminum flywheel pros & cons.

Heavy car = heavy flywheel. The flywheel stores rotational energy to get your lead sled off the line without bogging. Use a heavy flywheel when all your power is in the upper RPM range and you want some kick when you dump the clutch at part throttle.

Lightweight car = lightweight flywheel. Excellent idea for a car with a stripped out interior and lightened using all the tricks. Keep in mind that when you dump the clutch, the RPM's will drop if you don't have lots of power to keep them up. Lightweight flywheels may bog off the line, but are great once you get rolling. They are the best for road race type applications where the engine is constantly running up & down the RPM range. . Less rotational mass means the engine will accelerate and decelerate quicker.

I had an aluminum flywheel for about two weeks. Never again. Unless you drive it like you stole it all the time, it's not worth the money or the time for the marginal gains in percieved power gain. As stated above, they suck in traffic.

On the aluminum flywheel, I noticed how much quicker my engine revved, it was very noticeable, especially in first gear. That said, as the others have stated, they also make the car easier to stall, and harder to smoothly engage the clutch. My car is on the lighter side, and 3.73 gears also help, but the car was more user friendly with a steel flywheel. Stroking the engine has since helped, since that increased the rotational mass, helping to make up for the lighter flywheel. I'd probably still go with the aluminum flywheel, but it's not for everyone. I personally didn't notice a difference from the aluminum drive shaft, in any direction, I did it solely to lose weight, which it does do.