Imo use the Burson for a couple of months then put the Puresound back in. If it sounds better you will know after having had a break from it. But you still think the Burson is better then sell the Puresoumd as its still a current model. Once it is superceded, its more likely to go down in value.
Of course, it is easier to give advice says the man with 5 amps, 5 pairs of speakers....