This is really the lowest price way to buy this level of performance. How else can you get it for $1K? Ok you can buy a cheep PC, install BSD UNIX on it then implement RAID there and then connect it to your Mac Pro. But connect it by what? Gigabit Eithernet is 4X to slow.
I bought this Norco 4629 for $190
http://www.amug.org/amug-web/html/amug/reviews/articles/norco/4629/
It hooks to 4 drives without port multipliers, but it can do up to TWENTY with PM's.
A RAID 10 with 20 drives or a RAID 0 with 10 drives can do 453/404 R/W.
So that's $800 I save. If you did it with 500GB drives ($100 each), that's 8 more hard drives I could add simply for the cost difference between the two.
The only advantages the Apple card has:
1) Bootable (norco is not)*
2) uses existing drive bays (norco is external)**
3) S.M.A.R.T. works in OS X (norco does not)*
4) RAID-5 & 6 (norco doesn't)
* No card I know of other than Apple's does these things due to some weird thing Apple has done to the Mac Pro to mess it up.
** No other card does this, which is pretty cool
Now the Norco's advantages:
1) Works in Windows (Apple's doesn't)
2) Works with Port Multipliers to add up to 20 drives (Apple's does 4 max)
3) Less than 1/4 the cost ($190 no tax vs $999 plus tax)
4) Can be added aftermarket (Apple's is BTO option only)
Keep in mind, the Norco is the CHEAPEST 4 drive card I could find and it does so much more. There are other cards out there that do RAID 5 & 6.
For the record, this is the first 4 drive card for the mac pro I've seen made by
any vendor that costs more than $400.
So when you say $1,000 is a good deal, you really say it not knowing of any other options out there.