I have worked extensively with 1Bs in a nearly square room of small dimensions, such as yours. The harshness and boominess that you speak of may be the result of corner reinforcement and slap echo that result from how you've set up your system. I obtained the smoothest frequency response, and best soundstaging with the following arrangement: After dividing the room into 16 imaginary squares, each speaker was placed with the center of its front baffle at the interior vertex of the left and rightmost squares at the front of the room. The listening position was set with the listener's ears one square from the back of the room and equidistant from the left and right walls. The speakers fire straight ahead. At these distances, tweeter-woofer integration is strongly affected by azymuth. I used the threaded spikes on the stands to cant the speakers back about 5° from plumb. I like this better than setting up the speakers by the rule of thirds (i.e. Speakers one third out from the front wall and one third in from the side walls, listener one third forward of the backwall) which made the midrange too forward and seemed to generate lumpier bass response. Imaging was swimmier too.
The moral of this story is that playing around with placement can have a very large effect on frequency balance, smoothness and imaging. Its worth a few hours of messing about.
I agree with Tsugury that these speakers sound great with tubes. I've heard them sound splendid with a cheap 15 wpc ASL integrated. They sound unbelievably great with the Music Reference RM10 that Wes discussed. However, they also sound extremely good with the cheap 35 wpc NAD integrated amp that my son is using. The Musical Fidelity stuff is very nice. I would not be inclined to set the blame for your problems there.