Re: machines taking time to logon to domain
Are you sure the domain is stable? Run ‘dcdiag’ and report the results here. If there’s anything ‘stuck’ referring to the now-gone DC, that query action will have to time out and then start hitting the current DC, hence the delay.
You may end up having to clear garbage metadata out of your domain records using ntdsutil. There are lots of guides on-line to follow, but tread carefully, as ntdsutil is incredibly powerfull.