PCMag.com have a great "How to Buy a NAS Device" guide.
The guide looks at various NAS devices including Home Server specific:
- Acer Aspire easyStore H340
- HP MediaSmart Server EX487
- Lenovo IdeaCentre D400 Home Server
The Acer got 3 out of 5 stars whilst HP got 4.5 and the Lenovo 3.5. Each unit also gets a thorough review which looks at the design, setup, features and performance, which you can find here.