Well, I finally finished Arc III; definitely the best yet!
Ever since after Outlaw City was complete, when I was first introduced to Master of the Wind, it's been the center inspiration for improving my own skills; I've carefully watched and learned from the dungeons designs and the best dialog I've seen in any RMXP game (and frankly most commercial games!) to date.
MotW has a couple minor issues; the mapping is still a bit basic, mostly in towns, and sometimes the sprites can't convey the deeper meanings of what's going on in a scene...
BUT!
It's still easy the single best RMXP game around. The puzzles are top notch; they're always varied and they bring the maps to life, as ArtBane put it: "Design the map around the idea, not the idea around the map."
With complex event interaction, it's easy the best use of the Event system I've ever seen. Mix in that the dungeons themselves are NEVER a disappointment; they're as varied as the puzzles themselves, with different themes and with puzzle styles that never feel out of place, and you've got a smack-down combination.
I can still remember how impressed I was that the very FIRST dungeon in Master of the Wind easily trumped any other dungeon I'd played or attempted.
You will get as much from the MotW dungeons as you're willing to put into them.
Next comes story. With memorable characters that have their own issues and quirks, Master of the Wind has easily the most smooth flowing dialog of nearly any GAME I've ever played. The story itself is entertaining, and although it gets sidetracked at times, it's kept me waiting for the next installment without fail since I started Arc I.
Currently I think anyone developing games for RMXP should play this. You will, if you pay attention, learn so much about how to improve your own work it's not even funny. I say this from experience.
I'd also just like to mention; to those of you so concentrated on scripted systems, that MotW relies only on the most basic of scripts, using only a handful to create an atmosphere. Yes, the best RMXP game around doesn't have a ton of super custom scripts, it just has amazing gameplay and story. That's something to take to heart I think.