Am starting a new post, because this problem has now expanded. Besides the pausing, I'm now encountering situation where Search doesn't index contents. Not for pdf's, not for MS Office documents, not for the other file types where i have an ifilter installed. The only files being returned in searches are those where the search term is in the file properties. I rebooted, rebuilt the index (at least for the file system, haven't rebuilt Outlook yet), and that did nothing.
This is starting to get very frustrated. The issues with search have been going on for months, and instead of getting better it's getting worse. And clearly MS doesn't care.