IMHO two very different animals really. I own an Akorn in addition to other cookers, but I see it more as a grill/roaster than an all out smoker. I love the Akorn for indirect grilling and reverse-searing, and they're super efficient. People do use them for smoking with the use of a diffuser however, I just have not as I have other dedicated smokers. A WSM (though I've never cooked on one) I see as more of a smoker than the Akorn, and I bet it has more capacity too. I suppose it's all in what you wanna do with it. I'm sure some WSM users will chime in soon.
UDS, Akorn, Weber Red Head Kettle, Drum Grill, Gasser w/cobwebs all over it. I'm JD.