Everything I've read about the FPGA (Like the Analogue Nt) is that since it is hardware emulation, not software based like Retron 5, it is spot on.
Does anyone know if these FPGA's are not as legit as advertised? I haven't tried one.
I do hate to see that "the community" has pissed off Kevtris, and yes, Joe and Dave did mention him in their show. I know that Game-Tech US also prominently features Kevtris.
FPGAs in theory can have no lag, shearing, frame stuttering, or slowdown, as opposed to software emulators on non-realtime OSes. However, a poor designer can still make a shitty FPGA core that doesn't work accurately, so FPGAs are not a silver bullet or anything.
I have used a Minimig, an Amiga custom chipset recreation on an FPGA board, for several years, and it is pretty awesome. Not perfect, but still really good. I'd have bought a MIST emulation box a while ago myself, if it weren't for all the incomplete and experimental cores on that thing.
I guess it goes to show just how having a perfectionist like Kevtris designing the cores on the NT mini and Zimba 3K can make them far more attractive for being super-accurate.
Anyway, about the PCE, Kentaro in Japan had been working on an FPGA core for the PC-Engine for several years now, though his project is somewhat dormant/slow. His info page:
http://www.geocities.jp/team_zero_three/PC2E/english.html