wellllllll, let me tell ya ! having both and having used both, i almost think that they are to far apart to be considered competition. i know that doesn't make sense. the cga burns hot enough but won't really burn anything badly. the sj seems to get hotter and can burn yer food if yer not watching. the reason for this is that its easy to add a lot more charcoal to the sj. i would say the sj has a bit more room but it really depends on what you want and how you want to cook it.
anyway, if you need or can only have one then i would say the sj wins. but if you can have both then i think you would be extremely happy with the cga.