Just replaced my heavily used Ubuntu HTPC with a 6 watt AppleTV 2. Both run XBMC.
Specs of the old, silent HTPC:
- Intel Core 2 Duo E4300 1.8GHz w/2MB Cache
- Intel DQ965GF motherboard with passive chipset heatsinks
- Scythe Ninja passive CPU heatsink
- 4GB (2x 2GB DIMMS) ADATA DDRII 800 MHz memory
- 512 MB MSI N210-MD512H GeForce 210 PCIe 2.0 passive video card
- 40 GB Kingston SSDNOW V-series (Intel rebranded) SATA SSD
- 18x DL DVD+-RW Optiarc Ad-7170S 2MB Cache SATA optical drive
- Antec Sonata case
- Dual 120mm Yate Loon case fans
- Seasonic 330W power supply
- Ubuntu 10.04 AMD64 with XBMC
Video is just as smooth on the AppleTV as on the HTPC.