McIntosh C220 C2200 C2300 differences?

I am thinking of getting a Mac preamp to match my SS amp (an upgraded McCormack, perhaps a Mac MC275 down the road). Looking at the C220 and C2200 primarily. What are the sonic differences between these two? What about the C2300? A dealer nearby has a demo unit he would sell for $4600, but I don't know if it is worth nearly the 2x cost. I don't listen to vinyl