I don't hide it. I rotate randomly generated passwords quite often and we haven't had a hack in some time now (or at least, a successful one). People definitely nag you and it can get awfully annoying, but I think it's an alright trade off to making the site staff seem friendly and accessible.
Thing is having a user named Administrator and even having a user on id 1 with admin at all are huge targets. Our vB forum didn't have a user 1 and I actually assume it was a previous admin that was deleted but I am not sure.
Whats funny is User 2 and 3 were basically owners of the site with global admin. But any time the site was attacked they dumped user 3 specifically. No one ever went after #2.
When it comes to people getting bothered more often user #3 gets PM's and profile posts regarding site design development etc. When the truth is the person to bug is me and I was user 3128. Luck of being the new admin I suppose and no owner related title.
I wish there was an add-on that would allow you to use the Google Authenticator like I do with my SSH logins on the servers. Makes it nice as I use keys normally but I'm not always at a computer that has a key installed on the server (and don't have a habit of carrying them around on a thumb drive). Makes it nice to be able to log into SSH from remote if I am at a clients and need to do something.
I avoid the whole "Admin" username because that's where spammers try to force themselves into, etc. But the other weakness is that "admin" or administrator usernames in general makes you look like a faceless admin. No personality, no bones, no this, no skin, no that... you know, the usual.