This fascinating story on WHIO reports on tax valuations in the greater Dayton marketplace for the 2014 tax year (for bills first issued in January of 2015):
Montgomery County: ↓ 4.0 %
Clark County, ↓ 4.2%
Greene County: ↓ 3.0%
Miami County: ↓ 7.6%
Summit County: ↓ 2.2%