Hey,
Out of curiosity, what's the largest wiki to use Semantic MediaWiki?
That depends on how you defined "largest". If you want a list of public wikis (which of course is not complete) by property value count, then here you go: http://wikiapiary.com/wiki/Semantic_statistics
SMW is used on many hundreds of wikis, including those of governments and large corporations. It has been out there for years. People seem to be using it very successfully. It also has by far the largest third party community next to core itself. From my perspective a lot of the concerns typically coming from people whenever WMF usage of SMW is in question are uninformed paranoia. And there seems to be a good deal of populism going on as well, since apparently in some WMF related circles it is cool to hate SMW.
See also: some testimonials: https://semantic-mediawiki.org/wiki/Testimonials
Cheers
-- Jeroen De Dauw http://www.bn2vs.com Don't panic. Don't be evil. --