Just to compare tax situations, here's two bond ETFs and their yields:
VTEB, tax-exempt 1.96%
BND, taxable 2.36%
To me it looks like even the 25% tax bracket benefits from tax-exempt bonds. In the 25% tax bracket, BND yields 1.77% after tax versus 1.96% for VTEB.
Aside from that, it also allows you to have more space in your tax brackets for other things (like converting IRAs to Roth IRAs).