I have a Framemeister and a Retrotink setup in my game room. I have most old consoles, I've gone pretty crazy on getting CPS2 and CPS3 arcade boards working on consumer equipment. I've contemplated re-getting a CRT. Then I decided to check out the input lag on the emulators, since I felt the same thing with input lag and CRTs at school (Setup a retro arcade for my students last year). My conclusions? Using the 240p suite; Genesis GX input's lag was as good as a Genesis plugged into a CRT. This was me using a dualshock 4 wireless on a 10 year old Sharp LCD, which I would imagine had more input lag than newer T.V.s (Or less since there's less post processing). BSNES had 3 frames of input lag, which I find ironic since that emulator's author insists all emulators have input lag (Which was proven 95% false with my testing of Genesis GX), yet it was really only just his emulator that was bad. Between this revelation and the CRT shaders that are out there now, I feel like getting out of the rabbit hole. I find an emulator has too many advantages over original hardware on a CRT. I mean, I go between hardware for my Street Fighter games and emulator, and it "feels" the same. Are they the same? No, putting them side by side is going to show a different timer. But how often does anyone play anything side by side like that?
