I have two old, old Kettles, an 18.5" with firebricks as a heat block and a 22.5" with the Smokenator. They basically perform exactly the same and are both easy and great for smoking. I don't use them for grilling at all. I grill on gas.
I leave the bottom vents full open and control the grill surface temp with the top vent only. Once I got the hang of it I can fire them up quickly using a Minion method. I pile previously used briquettes in the center of my burn area behind the heat fence or in the Smokenator. Then I put new briquettes and wood on both sides behind the heat fence or in the Smokenator. Then I dump 15 or so hot coals on the old briquettes and put the lid vent and chamber probe opposite the fire. I can easily go 4-6 hours on one fill of Kingsford blue bag charcoal on a dry smoke. The Competition stuff disappears in half the time. I won't be buying it again. After a few initial spikes the temp settles down and will stay relatively constant for an hour or more before needing a minor adjustment.
I have a new WSM sitting behind me in the box as I type, a gift from my wife for me for Christmas. Can't hardly wait to get smoking with it. I also want to try using the lid of the WSM on the Kettle to see if it will work. If it does, I just might order a WSM replacement lids to use on the Kettles, giving myself more vertical room than the flatter Kettle lids offer. Suspect it will use more fuel though. Time will tell. Hurry up Santa!