Well, let me specify that I was able to integrate them seamlessly (to my ears) in a relatively small room (something like 13x18).
The only caveat is that it took a while to figure out how to place them on the Gradient woofers. Once their feet are taken out, the ESL's sit on whatever flat surface in a slightly bent way. Well, that is definitely not the right position. They have to be perpendicular to the woofer in order to obtain the best sound. It is possible that some of the complaints I heard above have something to do with the position of the ESL's.