Yeah, the phantom always sounded "fuller" to me, but analyzing that I realized it also sounded kind of hollow in comparison. A real center can take some getting used to if you're used to the "fuller" phantom sound, but it's worth it.

Conveniently at the same time I added a center to my 4.1 primary system, I upgraded my bedroom speakers from 2.0 to 5.1 with a center over the TV. Now in the bedroom it sounded so clearly better than what I had before, it didn't take too long for me to get used to the primary system either. However one member of the household liked using Dolby Music processing for a bit because it expands the center onto the left/right speakers, which made it sound similar to the way it was before. That didn't last long though.