I think it's a matter of personal preference whether the extra money is worth it. Certainly, there're diminishing returns. If I move from a Bose speaker system to an Energy speaker system, I'm going to see a huge improvement. If I move from the Energy to Aerials, I expect to see a big improvement, but as big as from Bose to Energy. If I move from Aerials to something better, I would expect the improvement to be even more subtle.

Same with the MC-8/MC-12. I absolutely love my MC-12, and wouldn't change it for the world. That being said, I had no problem recommending the 950 enthusiastically to Nostaliga, since I know that for his purposes, the 950 was more than sufficient, and a lot less expensive.

Jeff