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.

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. Part of the problem in such a small room is the speakers are not far enough apart and the focal point where they are aimed is sometimes only a few feet in front of the speakers. The false corners may allow you to angle them in or out to suit your taste.

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.

I have my Khorns in a room 17'X 21'. I've had the speakers for over 20 years in 4 different rooms (all smaller than this) and for the first time things are working well. Any room much smaller than this and it's tough to get them to perform at their best. I also have Lascalas and they seem to work a bit better than the Khorns in a smaller room.