I've got a 6.1.4 setup going right now and I feel no loss from dropping the center channel. Given that we're pretty much fixed in a center position when sitting at the computer, any decent L/R speakers can create the center image. I used to have taller speaker stands and tried an L/C/R setup above the 48CX pointing down but the L/R at ear level sound better to me. (angles are certainly difficult to get right)
Since Windows doesn't have a 6.1 configuration, I guess all this is dependent on your sound going through an external processor/receiver but in that particular case I'd suggest trying things without a center.
Since Windows doesn't have a 6.1 configuration, I guess all this is dependent on your sound going through an external processor/receiver but in that particular case I'd suggest trying things without a center.