I'm interested to hear what others think the shortcomings of the current crop of NetApps are. From my experience:
My biggest beef is that the upgradability of these things is low. It seems that when you buy a unit you are buying a capacity and improvements in disk technology don't raise it. For example, our unit uses 4 gig drives. Its max capacity is 14 4 gig drives. We'd love to put 9 or 18 gig drives in it, but the software doesn't support it. I realize 9 or 18 gig drives would raise rebuild time, but that risk should be up to us.
I also consider the high price per meg to be a shortcoming and because of it we are researching and developing alternatives.
Chris