As a member of the NatAmi team, I can give a little bit of information if you think to ask.
The NatAmi MX board is being manufactured in sample quantities as we speak. It is expected to arrive in the hands of the team members in January.
I share the lack of enthusiasm when comparing it to the likes of the Retro Replay though. The fact that we haven't had a working prototype to test on except the LX board hasn't helped matters any. The biggest advantages we have is that we have a much larger FPGA than what the Retro Replay board has so, given enough time, we will be able to make the NatAmi MX last a little longer than Retro Replay's useful life.
About the only soft cores finished are the N68050 processor core which should blow the doors off of the Retro Replay as it will clock at 100 MHz or better depending on what clock speed the FPGA for the MX model ends up with. There should be an article about the N68050 coming out soon in a Polish webzine.