If you want a change, the most significant change (for better or worse) would be to change your speakers. I think changes in your Source>pre>amp will be relatively minor compared with a speaker change.
I honest don't know which of the electronics I would change first for the biggest bang for the buck - I suspect the CD or preamp would be the most noticeable change. I owned the CD3 MKII and thought it was wonderful, I really don't know how it compare to this year's models, but it might have held up very well indeed. I would bring the CD to a dealer and compare it with the latest, if you notice a significant improvement - starting at the source proabably has the most implications throughout the chain. If the improvement you hear is marginal or sideways, perhaps a move to the LS27.
I honest don't know which of the electronics I would change first for the biggest bang for the buck - I suspect the CD or preamp would be the most noticeable change. I owned the CD3 MKII and thought it was wonderful, I really don't know how it compare to this year's models, but it might have held up very well indeed. I would bring the CD to a dealer and compare it with the latest, if you notice a significant improvement - starting at the source proabably has the most implications throughout the chain. If the improvement you hear is marginal or sideways, perhaps a move to the LS27.