The A's and B's are drives of a mirrored pair. You could lose,say, drives 1A, 2A, 4B, 5B and 7A and still have a functional RAID 0, because no single mirror is completely broken.
Ahh, okay. So you are using three times as many drives. So your chance of a single disk failure is 3n-1, but the chance of a double disk failure in a single stripe is... well, I'm not gonna sit here and calculate it out. I think in the end you might end up with better data protection (although not as much as one would think since your chance of failure is much higher), but it's a heavy premium. I always thought if any drive in the stripe set was down it would switch completely to the other stripe set, so that's good to know.
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Since we don't know how much all the EMC and related stuff cost, it's hard to accurately compare the two solutions. I bet it is much higher, and you said you would prefer the Netapps, which is good because you were sound failry pro-Celerra earlier, but it turns out you were comparing apples and oranges.
Personally I don't mind who prefers what just so long as all the facts are on the table.
Bruce