Khorn room size

I had mine in a 12' x 13' room, good corners.
No, it was not big enough. May work for you but I could not make it work, even after the normal tweaks:
Crites XO
Pipe insulation to seal them into the corners
Rope calk putty on the horn
3-watt SET (plenty loud for me), 150 watt SS, 100 watt EL34
Blankets and pillows all over the place
Resistors in line on the tweeter and mid

I could not get them to integrate so close to them. Not saying it can't be done but I'll believe it when I see it only.

As far as selling them if you don't like them - Only if you are patient and live in a bigger town. They are huge and you need to find a local buyer.

04-29-13: J_stereo
I enjoy the sound of my KHorns in a similar size room. However I built false corners for them using 3/4" plywood so I could change the angle of the speakers.

I agree the angle can be an issue.
I disconnected the Top Hat (houses the mid and tweeter) from the base (bass) in an attempt to do what you did, change toe-in of all but the bass. Close but no cigar for me.