Tony,
I have a 14 WSM and love it. I do not have an ATC, so I am going to speak about my experience without one. The WSM has been pretty easy to control temps, but it has taken me time and tinkering, watching the cooker, making adjustments through the cook. Now 6 months into cooking on it a few times a week, I have the method more dialed in and it takes less effort, but still have to mind the process. Even with feeling like I am getting the process dialed in I am still thinking about adding an ATC to my Arsenal of smoking tools.
Reading your original post, if you both want to get everything you need in this one shot and you want hit the nail on the head with your cooks from the start, and you identify as being a super busy guy, with all that said, yeah I think an ATC would shrink the learning curve and make your new WSM a true set it and forget it.
I know a look of guys on this site who run an ATC on the 14 WSM so hopefully other chime in also.