When enabling Windows to set system time via Internet, I'm presented with the following dialog:
Does it matter which time server I choose?
How would I know if one was "better" than the others?
Short answer: Yes
Whilst all NTP servers strive to maintain synchronisation with UTC, their distance from you, and the intervening networks, affect NTP factors such as latency and jitter. There is also the question of availability, not all servers are available continuously forever.
So far as I know, UTC and the stratum-0 NTP service is not overseen, regulated or provided by USNO, even within the USA. UTC was defined by the ITU and is based on TAI plus leap seconds (I believe determined by ERS) TAI is maintained by an international set of 70 laboratories (of which USNO is one but also including NRL in Washington and NIST at Boulder) and coordinated by BIPM in France.
I would use the ntp pool for your locale.
By running a real NTP client on a suitable system and looking at the stats
Looks like connorw600.info… would be a bad choice.
According to Wikipedia, Network Time protocol works as follows:
From this explanation we can admit that to have an accurate clock sincronization you must have low difference in the delay time that the server respond to your request and the time delay that you answer to the server completing the sincronization. So, if the server that you are running are far away from you(I mean, there are a lot of "points" or routers between you and the NTP server) the probability to have a different "path" for the ntp packets that you receive and you send is increased. So, from my interpretation of the case, the best server to sincronize your clock is the "closer" one. I mean, if you get a trace of the "points" between you and the server you would choose the one that have less jumps. You could use "tracert" command from Windows to resolve the best public NTP Server for you.
Also, remember that beyond these standard options, there are a lot of public NTP Servers on the Internet.
Short answer: No.
It doesn't matter. They're are all the same. More or less, they're backups for each other. Within the the United States, the Time Service Department of the U.S. Navy Observatory is the official timekeeper. All other mirror its time including corporations, and, specially, any U.S. government entities. Therefore, all the options available from the drop down are same time. Hence there isn't one that is "better" than the others.