Do I need a center channel?

Hello all. I wanted to ask this question again, a little differently.

I listen to 80% 2 channel / 20% HT. I have a very solid center image off my two channel. When I watch HT I'm generally alone and sitting right in the sweet spot. Will I gain anything by adding a center? I would just like to know if a well integrated 3.0 system will preform better than 2.0 system for a solo user?