MSB DAC II vs DAC III or others?

I have the MSB DAC II for 18 months, and plan to upgrade. Should I go with MSB III w/ full Nelson mod, or buy another brand in the same price range? Anyone know the sound improvement from DAC II to DAC III?
I'm doing similar research, but I thought I read that the were not much different electronical, that the Link III was just an easier ugradable version of the Link II either way you might want to check out MSB's Trade In policy Good luck
Yes, My understanding also is the Link I, II, & III are the same unmodified. Each improvement is just an easier upgrade.
Might consider checking Stereophile this month has MSB III review. Regards
MSB dealer told me that he couldn't tell the difference between a nelson upgrade or not...he says its not worth it, better to go to the updampler or power supply.