(ironically, despite my quoting Ace Combat 5's superb tagline re command response, Namco's late 80s PCBs seemed to have quite a bit of native input lag - as we've discussed in the ACA general thread)
Eight frames for PS4 BAC Final Fight did sound extreme to me, too - and still does, offhand. But one thing has revised my opinion slightly: The Lord Of King. I'd instantly noticed something was up while roadtesting TEH ROMZ, prior to its ACA release. Indeed, ShmupMAME reported 5f startup lag on attack - and this in a hack designed to cheekily shave down lag. Newest vanilla MAME gave same result. The PS4 ACA version feels identical to me.
Lordy is a relatively easy arcade game, but a one life clear is still pretty tight. At the time, I noted that the lag wasn't gamebreaking, but did necessitate a little more concentration than the otherwise easygoing difficulty would've.
Anyway, revisited it in ShmupMAME earlier this year, and noticed that besides the 5F on attack, it gave something like a whopping 12f on walk startup. I'm gonna check that today, just in case I'm exaggerating, but it was definitely a big old chunk on top of that 5f. I recall assuming that it was partially an artistic choice (big beefy barbarian bro in bikini armour takes a sec to move), partially code.
So now, I could see a game that feels acceptable turning in higher input lag numbers than I might expect. At this point, I do most of my oldschool arcade gaming via M2/Hamster and the odd chancers like BAC, Stadium and SNK40th. For sanity's sake, pending scientific testing, I file 'em as follows:
1st tier: feels great, no noticeable delay. (ShotTriggers and ACA consistently land here; if something has lag, it almost certainly did on PCB too)
2nd tier: can notice a bit of delay, but nothing insurmountable with practice. (I've gotten this from PS4 Capcom Arcade Stadium)
3rd tier: annoyingly laggy. (the PS4 version of Metal Slug XX feels like the characters are wearing lead boots)
Anything from the third tier down, I just won't bother with. I had a wonderful time one-lifing all the Neo Metal Slugs via PS4 ACA, just like I did on MVS (MS1/X/3). Firing up PS4 MSXX, I want to love all the content, but the series' gorgeous handling is spoiled. I almost wonder if its simply a laggy PSP emulator, tbh... regardless, for me, the pleasure of hard action gaming is 99.9% in the response. I'll put up with a helluva lot, as long as the control is tight (see SNK40th, a woefully buggy, glitchy product that squeaks by on decent response and a killer lineup).
