you are wrong, the bench says 6126 for the 330. its around 20% more than the 9600gt.Some people obviously doesn't realize that without benchmarks, you can't tell different GPUs apart.
http://www.notebookcheck.net/Mobile-Graphics-Cards-Benchmark-List.844.0.html
3DMark06
330M - 6539
9600M GT - 5063
8600M GT - 3269
The 330M is 2x the 8600GT and 33% more than the 9600GT.
But its no GTX 285M.
anyhow mbp are pro machines, not gamer machines. and their drivers are a way better than pc laptops, which implies better performances than pcs for an equivalent hardware. not so simple to compare. i also have a m15x with a gt240m and my mbp runs much smoother than my m15x when gaming.