Thanks for voting my comment up. Based on your request, I provide the following information. Let me know if you want to move this discussion to a private email discussion.
We have two published white papers to compare our engine with Lucene/Sor:
(1) A comparison white paper in the case of traditional keyword search: http://www.bimaple.com/files/Bimaple-Keyword-Search-Comparis... . We have a demonstration site to support instant, fuzzy search on Stack Overflow data (600K question titles as of January 2011): http://demo.bimaple.com/stackoverflow
(2) A comparison white paper in the case of geo-location keyword search: http://www.bimaple.com/files/Bimaple-Map-Search-White-Paper-... . We have a demonstration site to support instant, fuzzy search on 17 million US business listings: http://www.omniplaces.com . It has an iphone app at: http://itunes.apple.com/us/app/omniplaces/id466162583?mt=8
If you have questions, please feel free to contact me at chenli AT bimaple DOT com. Thank you.