I was patiently waiting for problems at ancestry.com to get fixed. Unfortunately, their staff seems to think it is better to announce problems on Facebook rather than their own website!! Poor choice IMO. The Ancestry.com home page would be where I would announce it.
On Facebook, they indicated the problems were fixed about 2PM Eastern Saturday.https://www.facebook.com/Ancestry.com/posts/208069476001300
If you're still having slow searching, or problems generating "Check Back Soon" responses, the problem apparently is bad data in your cookies. They suggest you clear your cookies.
If you're not in the mood to clear all your cookies, in Firefox, you can go into the preferences and click on Show Cookies under Privacy. Then type ancestry.com in the box, which then shows just the cookies for this site. Highlight them all and click on "Clear Cookies".
(Yes, others have posted about the problem, which lead me to Facebook. But the solution is buried pretty far down in that thread. I decided to post this as a new thread.)