I agree with JS-TX. You get plenty of support over here for whatever cooker you get. My brother in law has the acorn and he likes it. It doesn't seem to be up to the same quality as BGE or Primo, but it is by no means inferior. It is a good cooker, great considering the money. I love my Primo XL but would be just as happy with a BGE XL to be honest. I would not be happy with a smaller version of either to tell the truth. I have never seen a KJ so I cannot comment on that other than what I have read about them is that they are very good.
Honestly, you cannot go wrong with any of them. Just make sure you do not shortchange yourself on size. I am glad I have the XL and if I went smaller I know I would be dissapointed. Having all of that extra cooking space just opens your options up.
Primo Oval XL, BPS drum, Weber gasser