king indian vs queen indian

Both have tons of theory. The KID I think theory is more required to play the positions well, since the lines are filled with all sorts of strange little moves you won't find unless you study the theory.. sometimes only-moves. So you really need to study the KID day and night, like some people do, to play it at a high level. But the KID I'd say is more complex, so if you do know the theory maybe you have better fighting chances here.

The QID, while it also has tons of theory, can be played somewhat intuitively past a certain point.

Both defenses have specific variations that give them trouble...

The QID pairs well with the nimzo-indian, KID you have to play a pirc. Clearly the nimzo is better, the Pirc just sucks.

So I think I'd recommend QID before KID if you're pairing it with the nimzo.

But really if I'm playing the nimzo I'd prefer to play a vienna along with it.

GM Kotronias wrote an excellent 5 volume set on the KID. I have a friend who has always liked the KID. Plus he has always loved theory, the more the better he says, so naturally he has the 5 volume repertoire set and will play nothing else. I have GM Kotronias' 400+ pages wide tall book on the Tarrasch Defense. It's a big book loaded, but in it Kotronias writes that although the Tarrasch Defense has a lot of theory it does not begin to compare to the massive amount of theory in the KID and in the author's opinion the Tarrasch Defense is more practical to play as black unless one knows the KID's theory very well (which is very difficult to do because there is so much of it). As ibrust pointed out, one should be a very dedicated fan of the KID to play it, like my friend is.

Yeah for the club player who has to work a job I'd recommend the Tarrasch / Semi-Tarrasch before either of those.

Most of that sounds reasonable, but I don't follow you here. Surely one advantage of the KID is you don't have to pair it with anything -- it's playable against pretty much anything other than 1. e4. Of course, against 1.e4 you'd need something else (which could be a Pirc, but needn't be), but that's equally true of the QID -- in fact, it's a bigger problem there because you have to be ready for the QID against some lines and the Nimzo against others.

The one exception is the Jobava London (1. d4 Nf6 2. Nc3), where you have to play 2 . . . d5 to avoid transposing to a Pirc, but that's a fairly minor exception.