Cost-wise... eh. Going by list prices, EMC is a truckload more expensive. Discounts will vary the difference *GREATLY*. I just can't put enough emphasis on that last bit... At some point, depending on current pricing, EMC does become cheaper than NetApp. Half of our setup is disk intensive and doesn't require that much CPU. The other have is the opposite - we're melting a pair of 740s right now. Going by units of "1 cpu, 1gb cache, 200gb disk", EMC comes in cheaper after a small number of units. For us. YMWV.
But these wouldn't be units that would be equal comparison. What matters is primarily ops/$ and GB/$ for roughly the same levels of data protection. There are other factors (administration, features, etc.) but these are harder to measure objectively. I'm not doubting what you say; I'm just annoyed customers are comparing the two and yet don't appear to have numbers on this. Having more cpus per $ doesn't matter much if they need those extra cpus to handle the load.
Bruce