Uses 20 to 60% of a dual core for what seems like several minutes.
I got tired of this behavior and traced the problem back to samba (of course).
I am not a user of samba, I have other methods so the answer for me was to remove two samba packages.
samba-common
and
samba-common-bin
The gvfs-smb process is no longer loaded, for me, problem solved.
And I should add that I have tried this only once, needs some more verification.