Well it would seem I'm not out of the water yet either... :(
Now I have AWESOME connectivity... WHEN I have connectivity... on 5.0 Ghz. The SP3 falls into "Limited" connectivity" then snaps out of it. And sometimes, when the device is PARTICULARLY bored, it simply shuts off all network adapters on the hardware stack... that's always fun.
And I DID find a little-used channel to run on as well to ensure I wasn't having interference.
On the 2.4 Ghz channel, I get the same 53-72mbps as before.
So... square two... better than back to square one, but still an unpleasant user experience...
The new router DOES help out a lot, however!