I have the Veritas 9" round plate (PDF attached), if this is the one you're talking about. I purchased it primarily for hand held use with a plunge router because of its 1-1/2" guide bushing support. That said, I do have it mounted as a secondary router in my RT.
It was incredibly easy to center, drill and mount on my base (it comes with only the guide bushing hole drilled) with their great technique and included install kit. As you know but others may not, Veritas (LeeValley) is confident enough with their kit so as to offer you a free replacement base if you screw up on the first one, but it really is that easy.
If you're considering this for the granite top, be aware of the bottom-side routing shown at the bottom of page 4. This may up your milling costs.
Also, the plate is made out of a polymer / plastic and you indicated a preference for metal.
I have a ~15#, 15 amp "3 hp" router hanging from it with no perceptable sag.
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