If you're having long wait times when searching HUGE documents, increase your large object size. The default is 100, but 1000 is acceptable -- last time I checked, 1024 was the maximum for this value).
Increasing the large object size reduces the round-trip calls to the server for the next object, improving performance dramatically -- and as a side effect, it may also improve compression, saving you disk space.
After you make this change, it will only take effect on NEW documents that get loaded, so you may continue to have performance issues with older documents.