Did a bit of analysis this morning, comparing the 480i handling of the OSSC, OSSC 480i passthrough and the FM.
Setup:
Model 2 JPN Saturn.
Decathlete (Aka Athlete Kings)
Retro Console Accessories SCART cable (C-sync)
Panasonic 55VT60
FM settings - default except for changing HDMI Output to 1080p60
OSSC settings - default
TV settings - uncalibrated. SMPTE-C colour space
OSSC:
Pros - great colour. No combing. No jailbars.
Cons - Bob deinterlacing. Looking directly at static parts of the screen, such as text over a moving title screen background, made me feel kinda queasy. The 'bobbing' of the text, even at a viewing distance of 1.5-2 metres with a 55-inch screen, wasn't pleasing to look at. Graphics not as sharp as FM.
Verdict - probably fine as long as not looking at text directly or with greater viewing distance.
FM:
Pros - Sharp image. Very clean edges. Proper deinterlacing.
Cons - Very noticeable combing on certain 3D graphics such as athletes legs when running in game demo. Very strong jailbars on solid colours including menu screen and blue sky. Saturn jailbars (only on some models/units????) when used with the FM is a known issue with no current fix other than rolling back FM firmware versions somewhere around to 1.07 - 1.10.
Verdict - Not that great with my model 2 JPN Saturn. Need to test with other 480i consoles to determine if is the console or the FM.
480i passthrough:
Pros - TV correctly detects 480i signal and appears to handle correctly. No jailbars. No combing. No stupid bob deinterlacing
Cons - slightly blurred graphics compared to FM. Colour not as well reproduced as via OSSC.
Verdict - unexpectedly, this is the pick of the bunch as it doesn't suffer either of the main problems shown by the OSSC and the FM.
So, I'll hold out until FBX releases the 1080p profile for Saturn, but atm it looks like I will probably be selling the Framemeister after all. The only slightly blurred graphics shown in OSSC passthrough to the VT60 are less of a tradeoff than the jailbars and combing via the FM. Unless anyone can advise on FM setting that should alleviate this.
Given the VT60s awesome motion handling, colour reproduction and 480i deinterlacing, I'd even go as far as suggesting it as an excellent option for retro gamers - combined with the scaler of your choice. They're a few years old now so can probably be picked up for a decent price secondhand. And a quick Google will tell you how awesome they are at handling modern content. Just be mindful of image retention and incorrect handling of 240p over component.