Dog Hole Bushings and Bits

[yworkcb]

  Looks like the folks at Lee Valley have been listening to us .Making bench dog and MFT holes should be easier and more accurate . http://www.leevalley.com/US/wood/page.aspx?p=72602&cat=51&ap=1

 

[RobNJ]

I've been looking at those as well.  Am considering biting while they have free shipping this weekend.  My plan was to make a square template with three four 20mm holes based on my MFT.  On the fourth hole, I'd use the bushing.  So as I went along, three holes would have dogs in them, and I'd drill the fourth and so on...
Has anyone done something similar to this to make a large format MFT?  Any insight on how to best minimize any error?  I know most people default to the CNC route but I don't know anyone who does that kind of work, so trying to get creative!