I understand Mike's argument. If you compare the car to others in their classes, "simply amazing" and "not much of a performer" don't really describe the two cars. He wasn't comparing the two cars to each other, but rather their competition. Obviously the Z4 will outperform the IS300 on any battlefield other than the grocery store.

But, the "simply amazing" 3.0L Z4 is a full $8000 and 2 pounds per horsepower over the S2000. (2810 lbs with 240 horsepower)

Or 2.5 pounds per horsepower and $6000 more than the 350Z Track. (3225 lbs and 287 horsepower)

Just for fun:
MR2 Spyder curb weight = 2,195
Horsepower = 138 hp @ 6,400 rpm

15.905 pounds per horsepower at a grand total of $8,000 less than the 2.5L Z4.

Bleh. The Z4 is no more of a performer than the IS300.

Honda Accord Sedan EX V6: 3360 lbs w/ 240 HP
14 lbs/hp at $4,000 less than the IS300.

Nissan Maxima GLE: 3308 lbs w/ 255 hp
12.97 lbs/hp starting $1000 less than the IS.