From reading the documentation,
when syncing to a gps receiver,
it looks like it just syncs using the nmea messages,
and not the much more accurate transitions in the
1 pulse per second waveform on a modem control line.
Is this correct?

It looks like ntp servers can only be specified by
ip numbers not dns hostnames.
It's nice to use hostnames,
eliminating the need to reconfigure when the operator of the server moves it to another ip,
or to randomly assign servers from pool.ntp.org

For robustness and accuracy
the documentation on the ntp websites
recommends syncing to 3 to 5 servers,
but routeros only supports two,
a primary and a secondary.

I don't see sync events, etc.
in /log print

I'm just curious... Why does it matter if your AP, client radio, or router is a second off?

Scott

in my case i want it accurate so all my computers on my network can sync to the routeros box with a gps time source on it.