Actually the Deal with the Rail Blades is ( The Production Run is made Meaning, a batch of 606's are made, 696's and so on. when this is done they go into what they call a "BLADE POOL" this is where the blades are weighed and matched **Perfectly*** with there Mate.. No need to balance at all.. Matt is Very Detailed Oriented in this Process.. They are Spot on matched.. I have taken an unmatched set and Married them by re balancing them and they worked just fine, However with out Contractual agreements (Team Synergy Pilots) we are required to run our Heli's in Perfect Condition including the Blades... the only thing we get away with is the (BLADE SCRAPES MARKS) on the tips... That's just Bragging rights for us..lol and yes the Bigger the Scrape the better..
BR,
Kevin