I tried an experiment today using a Defintive BP7001SC as the Center Speaker.
Contents:
1) Underworld Evolution BD
2) Dire Straights Brothers In Arms SACD
3) Sheryl Crow SACD
4) Crowded House DVD-A
5) Eagles Hell Freezes Over DTS-CD
6) My favorite 21 songs compilation CD
Concerns:
1) Not focused enough soundfield for dialogues since it is a bipolar speaker, instead of direct-radiating.
2) Placement issues adversely affecting sound quality since it will be placed between two large 53" Bipolar towers.
I'm happy to report that both concerns were laid to rest.
First, it sounded very focused just like the CLR3000. So dialogues sounded extremely natural and real. Furthermore, when the Center channel demanded more bass (explosions in movies, bass in 5.1 music, etc.), the BP7001SC provided abundant amount of powerful bass. In this respect, the 7001SC sounded even BETTER than the CLR3000 as the Center speaker.
Dire Straights SACD was a great example. Just about every song had awesome bass coming from not only the LFE/Subwoofer, but also the Front Left, Center, & Front Right speakers. When I placed my hand over the subwoofer drivers of the Trinity, 2 BP7000, and BP7001 Center, I felt tremendous actions from these woofers.
Second, the huge BP7001 Center did not affect the sound of the two BP7000s. The BP7000s are prone to placement conditions. I mean certain positions and certain objects placed close within proximity can adversely affect the sound quality. But this large Center tower did not cause this problem in movies nor music. I also played my 2.0 compilation CD for measures. It sounded just as clear as it always does.
Now I will have to sell my CLR3000 & 7001s and buy 3 more BP7000SCs so that I can have 5 identical speakers.
This also proves 2 things to me (and not everyone else

).
First, using Bipolar speakers as the Center speaker is great.
Second, using 5 identical speakers is ideal.