I think there will need to be more testing on the actual fakemeta natives vs the engine natives. As for now the only argument has been fakemeta conversions (stocks that emulate the engine natives), but
http://forums.alliedmods.net/showthread.php?t=65427 just puts it to fakemeta, there is not any fakemeta conversions so you can't completely say that fakemeta is slower in that situation.