Yeah, I used medium on both and let it preheat a good while. I wasn't sure what temp I wanted so let it set at medium low for 10-15 minutes before deciding that wasn't high enough and turning up the burners.

Didn't seem to affect the rest of the range anymore than having three burners (I had a pan of eggs going too) with three individual pans would have. Took forever for the griddle to cool off enough to pull it off the stove though. I would guess that'd be the case with any heat source, that's a lot of iron to cool.