Has anyone here any experience with 1stair.net?

I've been checking some possible upcoming routes for me and the fares in First or Biz have been excellent, usually 1/2 off the published fare. Air Canada via YYZ and United are two airlines that come up frequently for me.

Yet I'm weary to book through this service. Is it a consolidator? Will the fares earn full elite qualifying miles, including the class of service bonus? Can you upgrade from Biz to First using certs or miles on these fares? Any other "bewares"?

-BizJet