Got my copy of the Famicom version of NG3 and beat it. So the original Trilogy is finally finished for me.
It's definitely the easiest of the games, no contest, though if you can beat the NES version (by comparison the hardest of the games) my hat is off to you. I couldn't get past Act 2-2 in that version whereas I got my first Game Over in Act 5 in the Famicom version. I honestly struggle to think of a game that received so many changes to the difficulty between versions aside from some of the localized games that Working Designs did.
All that is left for me of the original series is to check out the weird one-off titles or beat the original game final bosses without the Spin Attack. The Sega Master System one-off has been high on my list for a while to obtain a copy of. Hopefully the rumors of the Switch port of the reboot Trilogy comes true. Also picked up a copy of Dragon Sword a few months back but have yet to play it.
Would suspect Ryu would take the most from the new games & DoA, though I would hope that at the very least Sakurai gives him some standard sword slash attacks to mirror the original Trilogy, not unlike what Simon has with his F-Tilt & F-Air. Also give him the Windmill Shuriken.