Are there many differences between the 15" 2,2 gHz and the 2,4 gHz, because the 2,4 is much more expencive than the 2,2. Is there like very much difference in speed?
The main difference is in the GPU. The 2.4 GHz model has a GPU that is a step up from the 2.2 model. The GPU also has double the RAM on it, which should give a solid boost in gaming and make it a much more future-proofed GPU.
In terms of regular use, if you're not a gamer or use software that highly utilizes the GPU, you would be better off with the 2.2 GHz model.
How much would you say Photoshop CS5.5 uses GPU?