you say that now, the spee6 is ripe for modification and the market is really warming up.
i opted for the xCel from CPE. i looked at the MS CAI, but it was expensive and not as well made as the xCel. now if you can get one for "free", thrown on the deal, i'd be all for that. but at retail prices, no way. the CPE is superior. someone posted a threat comparing each of the CAIs available with pros/cons/prices. do a search, it's in the MS forum.
edit: here are soms MS CAI threads found with search
http://forum.mazda6club.com/index.php?show...114&hl=cons
http://forum.mazda6club.com/index.php?show...307&hl=cons
http://forum.mazda6club.com/index.php?show...099&hl=cons