I use the guru. I am a noob on the WSM front. I have had, to date, 5 cooks with the WSM.
The first one I checked the vents and temp every 15 minutes and it was a serious stress day. Good Q. Second smoke was similar, but without the stress and a full water pan. After the third cook I got the Guru.
I have had two cooks on it and I won't go back. Worth every penny. You don't touch the bottom grates at all, so that is eliminated from the equation--They are all closed. After the dark smoke is gone you cut your top vent back to a sliver and let the Guru do it all for you.
I like making Q, and I LOVE eating it. But tending a pit every 15 minutes and worrying about heat was not for me. Is 265 good? What about 275? 285? 292? And how long is that ok?
Now, I am learning that the WSM and Q in general is relatively forgiving. But why not just set the WSM for 240 and rest assured that it will stay there? It works.
I bought a WSM so that I could MASTER BBQ. Brisket, Pulled pork, ribs, smoked fish, etc without heating up the house. I want to be able to consistantly produce far superior BBQ than you can get at any restaurant within 100 miles of my home.
And for me, having to check the vents every 15 minutes just isn't worth it. Get an ATC.
I love my Guru. To answer your main question: YES!