I've had 2 Nortons so far.
The first one I completely wrecked trying to flatten some old Arkies. Basically turned it into a bowl in spite of my best effort to use the entire surface. This was before I discovered the DMT or made the connection that a flattening stone could be soft enough to get out of flat. That said...I'd rather wreck a $30 Norton stone on an Arkansas hone than a $60 DMT.
The Norton hone does do better lapping Arkies than a worn DMT. Slurry is your friend in that endeavor. I find the key is 100 laps on the Arkie, 10-20 on the DMT to keep the Norton flat enough to get the job done. Saves wear on the DMT, use that for heavy razor grinding and stones that don't suck out loud to flatten.
It also gets better after breaking in. Right out of the box it leaves some pretty deep scratches in everything. My Current Norton flattener cuts pretty good without making deep scratches. It's also about as flat as my DMT can make it.
For most endeavors I side with folks that like a well worn DMT. For things that are liable to tear through/finish off a DMT, or cost $50 or more in sand paper to flatten, there's the Norton flattening stone. Fortunately those hard naturals don't need regular flattening and burnishing.