Re: Lexicon MC-12 and high end processors, you pay for the name.
First off, similarities in back plates are common, but the two you point two are significantly different. Building an I/O board isn't too tricky, you need connectors and to have them spaced out, so sometimes you will see the same one on different manufacturers gear. These two are somewhat similar, but different enough as to preclude them being the same at all.
Second, Lexicon and HK are in the same parent company, so similarities are not to be unexpected in the fundamental design, the differences frequently come in other areas than the digital cards. Look at all the new receivers decoding the new audio formats, so far only two (one really) chip maker enables them to do this, so are all receivers the same? By your logic they are, and I don't agree with that. Power supplies, analog sections, case design and build, potentiometers, quality of resistors and caps, all add up to differences in sound. Sure, the core chipset is similar. If that was all you needed then go buy a $200 generic Korean POS receiver and discredit all the high end units as junk!
That is not the case however so I think you need to rethink your argument. FWIW the boards you displayed, and those on your links are similar, this doesn't surprise me, but they are also different reflecting how each company has come to deal with them for themselves.
If you think the HK is the same and sounds the same to you as the RV-5, then buy it and leave it be, be happy you didn't spend the extra cash, but I disagree with you that it is 'the same'.
Ken Taraszka, MD