I think that UBERNES, UKNES, and Return to Roots have diverse enough systems to make them not superior to one another and merely different. JNES is enough like UKNES that it isn't apples and oranges. But UBERNES was foundedto create a Unique gaming system, I started the series to create a new system combining the greatest parts of all the NES serieses and adding my own flair with the Alternate History theme it took, RTR is old school style, a beautiful embodiment of the original idea the pinnacle of the unmodded NESes, even though it's moded, and UKNES is the base for every other NES that's been tried here, the simple purchasing system found in the best UKNES's allows even rookies to catch on quickly, but it takes great skill and luck to succeed regardless.
JNES is the path UKNES would have taken had it continued the path away from the original, It's complicated but can be rewarding even if you never understand what you're doing.