It depends on the pot/pan. Stock pots and the like not much since they are pretty straight sided once you get above the roll from bottom to sides. Pans/saute's and pots that flare as they go up, a good bit. For example, I have a lot of All Clad pans and saute's that clear the island trim as they flare out from the bottom and center pretty well on the back burners and did not with my other configuration. Also, you will hear a lot about condensation fromt the oven vent whether you use island trim or one of the riser trim/vents, especially with a SS backsplash. Although we have a tile backsplash this time which probably helps reduce this, Ihave no residual condensation from the vent during oven preheat with the bump out. I did have a SS backsplash behind my last range that did not have a bump out and the condensation was very noticeable. However, this presents more of a cleaning nuisance than anything else b/c the condensation leaves dried water marks on the backsplash (especially SS). Anyway, its not a must but it is very handy and I really like mine. If you do it, make sure you bump out the vent hood accordingly which is not hard either. In my case, we were using a custom hood and hood liner so it was simply a matter of designing the hood enclosure to match the depth of the range with the bump out.

I didn't do a lot of searching before choosing my KA 6 burner. It is installed, but not yet hooked up. But one thing I really like is that the granite gets cut in under a flange, so there is no "crud crack". Another thing I like is that my counter run is extra deep at 27" (29" granite), so the rangetop was set back nearly to the wall and nearly flush with the countertop. Here is mine, followed by the floor model which is set in a standard run and protrudes an extra 3+ inches.

I'm just bumping to see if anyone popping in has reviews on the KA rangetop.

What is the CFM for the hood your wife likes? W/ Wolf gas, I would suggest at least 900 CFM. What I don't like about that hood is the MESH instead of BAFFLE filters. Baffles are so much easier to clean. --- Suggestion: get a 42" wide hood, so that gives an overhang of 3" on either side of the range top, which helps capture in a lot more steam (less damage to the side upper cabinets). My DH has been caught w/ the induction cooktop steaming away, when he's preparing his morning coffee, not remembering just how quickly water boils on induction. ----> can I persuade you to consider INDUCTION cooktop? I love my Miele 36". --- May not apply to ALL Broan, but my gf's Broan hood is wicked loud, so loud that she hardly turns it on. --- Remote blower = more expensive, when I was researching for one to go into my 42" copper hood. So I switched plans and went with a 42" Kobe 1100 CFM. good luck, Amanda