I find it interesting to see how bicycle disc brakes are going through the same evolution as motorcycles, but 30-years later (same as cars 60-years earlier). We start out with fixed-rotor/fixed-caliper single-piston brakes that eventually evolve into floating-rotor/fixed-caliper dual-piston brakes in the end. The floating-rotor does away with a lot of the squealing, shuttering and uneven wear issues as the rotor will self-centre between the pads.
I kind of object to the Park tool site's procedure since it does make the rotor flex more than necessary. There is really no relationship 1:1, 1:2, 2:1 between the two sides that makes sense because they're really not related. What I like to do is:
1. set fixed/stationary pad 1-2 clicks out from where you can hear it rubbing the rotor (this setting is fixed regardless of spacing on other side)
2. set moving pad as may clicks out as necessary to give you the lever-throw before engagement you desire.
This minimizes the amount the rotor flexes and leads to flatter contact between the rotors and pads. I like this procedure here:
http://www.twowheelblogs.com/avid-bb...set-and-tuning