Conrad-Johnson Sonographe S250 vs. MF2250A

Looking at Conrad-Johnson SS amps in the 125 wpc range. Can anyone comment on sonic differences between the Sonographe S250 and MF2250A? Is the MF2250A worth the $800. or so difference in price?

I need to replace tube monoblocks and would like a smooth, natural-sounding SS amp, if such a thing can be had without spending huge money.