I'm going to underscore Shawn's point, just for kicks.

Given what you've said here and in other threads, I think that "Seamless" and "Center Channel-designed speakers" are going to seem mutually exclusive to you.

The only way to ensure that you're not frustrated by trying to match them is by getting three identical speakers. That way, you KNOW that the only reason why you might not get a seamless soundstage is because of your room.

Unless you remove all the other factors, you're going to wonder.

bibere usque ad hilaritatem