Not that cooktop from Dacor, but I have a 30" distinctive all gas range - so the burners are similar as is the pattern on the grates over the burners. I have the exact 18k btu burner, a pair of 15ks and a 10k btu sealed burner.

I found the cooking surface to stay fairly cool (as these things go). It is noticeably cooler in operation. I think that's some due to the grate design and some to the odd-sounding SmartFlame thing claiming to lessen discoloration of the grates. I like the tine spacing on the grates, ignition works well without extra clicks, re-ignition works well too.

The burners develop good, even heat across the bottom of pans - much more than the previous 15k dual ring burners. I think its something to do with the way the flame bends back up towards center. This is mostly a great thing.

So, then ... these two not so good issues.

They call the center dual ring burner a simmer-sear burner which is a pretty apt description. It can simmer medium sized and above cookware and it can sear pretty goodly. What it has difficulties with is "low." The central burner head puts out some btus - I forget if its 3k or 6k but I think it's 6k. The way Dacor did the controls on mine, the outer ring turns down, then off, then as you keep turning the knob, the inner ring turns down. When you're trying for low, meaning the outer ring is barely on, the inner ring is still on it's high setting creating a big hot spot.

Problem 2, the level of heat produced when the burners are at the position marked simmer. I found it to be not a simmer on the other three burners - but the 10k can be made to work with a simmer plate (not included).

You should be able to get something resembling simmer using thick bottom cookware on the 9k burners and most pans on the center burner - with the center burner and a simmer plate producing the best result.

This is just an observation about the burner layout on the cooktop with the "big one" in the center but make sure you can fit the cookware you normally use when a big pot is in the center. Also, think about using it is like if the pot boiling the corn or pasta or whatever is in the back where the higher powered burners are - will there still be room to fit a pan for searing on the center burner. Alternately, if you end up using a rear burner for searing, is it placed so you can comfortably reach it?

If the burner pattern doesn't work for you, perhaps consider the 36" range top? 6 burners with controls on the front.