IMO it's fine but I definitely wouldn't allow it in a corporate environment. For a family system, I think it's perfectly okay.
It is supposedly more secure but there have been issues with it already. I think it still needs some aging. This talks some about it but I'm sure you can find more articles with google. http://www.zdnet.com/article/windows-10-will-let-you-say-goodbye-to-passwords-forever/
It's susceptible to human problems tho.. If you use the same 1234 pin at every machine you use, anyone who sees it will know all your logins.
its less secure by default since there is 9999 possable combinations it can be brute forced cracked in fact you can probably load a linux distro if you wrote it right and use it to hack pin in under a minute
It's supposed to be used with hello...but the pcs that support that aren't out yet..may be on wednesday though.
of course u would not use the same PIN on all machines....lets be realistic here passwords are as vulnerable as PIN in todays world.
If you use the same "password1" password at every machine you use, anyone who sees it will know all your logins In fact, it is worse if you use a password as anyone who sees it can log into your Outlook mail, Xbox account, onedrive etc from anywhere, whereas with a PIN they can only log into your local machine No, if you enter the PIN wrong more than three times it falls back and makes you enter your password this has changed, now it makes you enter a "challenge phrase" to prove you are not a bot