Earlier this year bought a whole bunch of parts from the US to do a major service, clutch, front discs etc. and then had them reboxed and shipped to me by a mate in Calif.
Included were a set of EBC front brake rotors/discs bought from JC Motors in CA. Now I'm assuming they just grabbed what appeared to be identically marked disc packets from their inventory shelf and shipped them off.
When I got them in Oz, they sat on a shelf for a couple of months waiting till I stripped the bike down.... well I got a surprise when I eventually pulled them both from the packets... different hole patterns, but marked as same disc model, MD616.
Thought it would be a pointless exercise going back to JC Motors as it would likely involve buying another matching disc and shipping it out at high cost, so I installed them with new pads and tested it out... Brake shudder under hard braking... but still pulled up OK. No time to do anything before our upcoming trip so got on with it.
Back from the trip, I've emailed EBC brakes (UK) through their contact page to query the different patterns and brake shudder issue.
Their Motorcycle Data & Technical Manager, Jon Wright, has come back to me and suggested they should have been the same hole pattern and asked for pictures of rotors and shipping packets, which I've done. From the pics he's identified one of the discs as from an early stainless steel batch of their "new" style hole pattern (scraper slot system) which can be used on either side of the bike, where as the other one was definitely a right-handed side disc. He's also suggested that since that early batch they've started heat-treating the discs to avoid rotor scuffing (evident on my disc after only 2500km).
The best part.. they are going to ship me 2 new discs, and new pads, to replace both at no cost to me.
That's gotta save me at least around $400-$500 all up with shipping costs to get rid of this brake shudder.
So, a big (pre-emptive) thanks to EBC UK for coming to the party to sort this out.