[aprssig] UHF APRS frequency for U.S.

[Bob Burns W9BU]

What is the consensus opinion as to what 70cm band (UHF) frequency 
should be used for APRS in the U.S.?

I know that Bob Bruninga WB4APR suggests 445.925 MHz on his web site. Is 
that well used around the country? Is that frequency protected by the 
various amateur radio frequency coordinating bodies around the U.S.?

Thank you.

Bob...