99.999999999% of TV and movies that are encoded for 5.1etc sound better with a center channel. 2 channel can sound ok, but they simply cant and dont sound better than with a center. If one is not watching shows encoded for surround sound then it is no big deal but few, if any, are. A center channel is better if matched, BUT, as long as they are close then that is better than no center channel.
I have never heard the BA speakers you got, but I am not surprised they sound better than the Elacs. The Elacs are some of the most over rated speakers. I fully expected to be blown away by them when I heard them for the first time a few months ago and they sound, wait for it.....ok. My old Polk RT25i sound better to me and my Polk TSX110s sound about the same as the Elacs. Add to the fact that the Elac are searingly ugly just made my disappointment even worse.
Like a poster above says, the center does most of the front duty (as it should) for shows encoded for surround (3.1/5.1). Since I far prefer two channel for music, I have two systems in the front room, one for music and one for surround. I placed the big center low and angled it up and even though the front main HT speakers are mounted low it sounds fine because the dialog etc from the front channel comes from the center. I have rear surrounds and a sub by the couch. I know not everybody wants two systems but it was best for me. Almost every system has some compromises so dont worry about not having a fully matched system.Sony receiver was one I was thinking about getting, it is a solid choice for HT.