This was already the case with the Mk3 - they were all streamers too, so in that sense there should not be much change in terms of 'feature redundancy'. Feel free to outline your system a bit more specifically and where your concerns might be if you would like me to try and address that a bit more.
This is two subtly different things - without an output module and using the normal on board USB, yes I would say the performance is relatively comparable with the favour on the side of the STREAM1+LPS1. When you add a module to it, it does indeed get more costly - and the sound quality goes even further ahead of ZEN Mk3/PULSE towards ZENith Mk3. You do then get the other quality of life benefits of 3x operating speed, new IR remote support, new accessible storage bay and so on. Our starting price has indeed increased, but so has the starting baseline of performance.
The used market options will always be very comparatively compelling and I think it affects all brands. It's like a car; the second it's driven off the forecourt, it suddenly loses a lot of its price from being 'used'.