I am currently using the outer two speakers of the Paradigm Millenium 20 Trio as one 4 ohm speaker (instead of two 8 ohm speakers) as my center channel. I used the Trio as my LCR until I started to build my dedicated theater room, at which point I bought two Millenium 20 towers to replace the LRs. The center was just not "there" enough for my aging ears. Since I already own the Trio, I thought I would do a free test.
Here is the Trio:
My opinion? It sounds much better. Not just because I thought it would. I was going to buy a new center and use the Trio as my rear right and left surround instead, since I needed to buy those anyway. I was surprised that it made enough of a difference that my wife said she could hear the voices better. I told her I was doing a test and to tell me if it was better or not. You can always trust a wife to tell you if your experiment failed...especially when she wants a problem fixed.
For me, the test was completely free, so nothing lost if it failed...and I was going to have to spend more money regardless of the outcome. Is the sound "pure", "correct", etc? I do not know, and honestly do not care, since it sounds better. Same reason why I bump up the db level of the surrounds after my room correction system is done with them...I like it better that way, and I am only here to please me (and the wife, of course).