I own a CJ MF2300A and it is hard to imagine a better sounding amp. I am quite pleased with mine. Although I have not heard the 2500A to make a comparison, the MF2300A garnered perfect reviews on audioreview.com which includes my review. The most profound difference would be the older MF2300A uses mosfets output devices and the newer 2500A uses bi-polar. Mosfets have a more tube-like sound than bipolars however they tend to clip a little sooner than bipolars. I have yet though to get the clipping indicators to even blink on my MF 2300A regardless of volume level. I would like sometime in the future to compare CJ's newer models to my MF2300A.
