Conclusion: The Netgear ReadyNAS NV+ is an excellent combination of small-business RAID muscle, gigabit throughput, and home-oriented media features. It's expensive, but worth the price if abundant storage, fast transfers, and RAID reliability are what you need.
Pros: Fast transfers. Supports the three major desktop OSs. Granular performance-tweaking settings. Well-behaved network client. Many features.
Cons: Some parts of setup are tricky. Attached USB hard drives must be FAT or FAT32, not NTFS. Expensive.