Audiofun, I am enjoying living vicariously through your DAC reviews. I have heard great things about the MSB Platinum and the Playback Designs - it will be interesting to hear your impressions of how they compare.
One red herring for me in this thread is the comment that the Weiss and Berkeley sound similar and that if one isn't impressed with the Weiss then they won't like the Berkeley. I think you will find Chris Connaker's review on Computer Audiophile to confirm this point. Now, that being said, as good as the Berkeley is to my ears it does have a HF "zing" on CDRB.
The other thing about the Berkeley, which may be true on other DAC's as well, is that it is sensitive to incoming jitter and noise. In other words, to hear the Berkeley at its best one needs a very high quality AES or SPDIF interface. The Lynx AES16 is nowhere near good enough IMO. As I posted above, a Legato async USB-to-SPDIF converter made a dramatic improvement in sound quality. Berkeley is coming out with their own async USB-to-AES converter which I suspect will produce the best sonic performance.
Anyway, keep us posted on your continuing quest. Have you thought about trying a Metric Halo ULN-8 DAC? This unit has gotten tremendous praise from both the pro audio and audiophile worlds. You need a Mac with a firewire interface and a DB25-to-XLR or RCA converter. The ULN-8 has a built in pre-amp and can function as a digital cross-over.