Has anyone had problems booking Aulani with a check in date in the middle of the week? We will be in CA 4 days prior so no way to check in on a Sat or Sun.
As long as there is availability, you should not have a problem coming in mid-week. Because Disney is not a traditional timeshare, they allow you to check in on any day of the week.
I think it just really depends on what time of year you are going... if it's during a school break time it will be more difficult than when the kids are in school as less people will be trying for those times.
Also, in my checking the website off and on, I have noticed that it seems to me that weekends tend to book up more solidly (like Friday through Monday). Not sure if thats local DVC owners, but perhaps... so in that case it might be better to start your reservation mid week.