Key legal question
Whether the taxpayer's tax domicile for 2006 was in Solothurn or Wyssachen/BE.
Extracted holding
The taxpayer's center of life and tax domicile was in Solothurn for 2006.
Extracted reasoning
For an unmarried employee over 30, the presumption favors the work/week residence. His weekend ties to Wyssachen/BE, though real, were not strong enough to outweigh the substantial personal and economic connections to Solothurn, including work, residence, and leisure activities.