Kid vs Benoni

play the czech benoni. Its a mix of the two. You have the pawn on c5 but you still play e5, f5, f4, g4 and crush your opponeny

The KID, The Czech Benoni, and the Modern Benoni are TOTALLY different.
Of the three I'd say the Modern Benoni is the most beautiful and the most difficult to play.
in the modern benoni there is a pawn on c5. in the KID there is a pawn on e5. In the czech there is a pawn on c5 and e5. czechmate

I play the Modern Benoni, the Czech Benoni is completely different. The modern Benoni can be quite difficult to play (imo), but it offers an unbalanced position. I like unbalanced positions, I play the scotch gambit as white and the french vs e4.

What makes the Modern Benoni so difficult over the board?
The cramped position and the weak pawn on d6. I am no expert on the opening (I think it's strategically dubious) but if Black can manage to trade a pair of knights he should be OK.

It is also worth noting that the Modern Benoni is extremely tactical. There are many situations where a natural recapture will actually bury the player ahead in material. It does lead to really cool positions though. Also lots of white players may try to avoid it. If you want to learn more about it check out these videos.
They are an hour apiece but it is very useful stuff if you can remember any of it.

I think the modern benoni works because tactics and that's it. I don't think Black can get far without being tactically strong. Otherwise White can just do whatever he wants.
I think you can get waaaay farther in the KID just knowing what you're doing.

I play the KID. I happen to know it very well and score quite well with it in all time controls.
The benoni... I lose with it if I play black, and if I play as white. It's a mystery to me.
As black with the benoni I feel very uneasy in the positions; one false move and i'm going to get crushed (which i do)

What makes the Modern Benoni so difficult over the board?
The cramped position and the weak pawn on d6. I am no expert on the opening (I think it's strategically dubious) but if Black can manage to trade a pair of knights he should be OK.
Thanks for the heart attack.

The mainlines of the Kings Indian have nothing to do with the mainlines of the Benoni, the structures, piece play and plans are different, however you can in some occasions have mildly similarities between openings.
In my opinion you should stick with what you know, openings are not your priority when you are Class A USCF and the KID is a fairly solid opening if you understand it.

The 4 Pawns Attack against the Modern Benoni is really scary...
Maybe for an unprepared player. For a prepared player nothing in the opening is scary.

I have to say that @Nic_Olas comment is spot on, the benoni is not so intuitive and one wrong move can really screw you up, the funny thing is that you won't realize it. You need to be really strong at tactics to try the benoni. I won't go into details about lines, but the videos mentioned by @Nic_Olas are great material.