I'm a little bummed that Swordfighters don't have little shields like they do in Find Mii, or that none of the Mii Fighter categories can use any magic attacks. Heck, I could totally see a fourth "Magician" category working, with things like a red magic fire tornado slowly crawling forward, or using light-blue ice magic to create shattering ice blasts as the character jumps upwards (sort of an Up+B recovery).
Heck, there's twelve shirt colors and twelve possible custom moves (three choices for four slots), so Mii Magician could've had a special move representing every color of shirt. Mii Force and Find Mii II showed a bit of creativity behind the color attack system, and I would've loved to see a bit of representation from the Mii Fighter "home series"... instead of mostly having cloned variants of special moves from existing fighters (Gunner is ESPECIALLY guilty of stolen moves).
That being said, Find Mii helped me create one of my earliest OCs of all time, starting from a simple sword and magic user (literally ported from Find Mii) and eventually becoming a great adventurer with her own pool of attacks, a group of friends, and a tiny pet triceratops... it's a long story. I'm definitely going to be using her as one of my mains in Smash 4 (Swordfighter seems the most likely due to her roots), since the Mii Fighters all look just as interesting (and viable!!) as the regular fighters. Also, I think it would be kind of neat to main the Swordfighter; most players who have their hands on JP Smash 4 have been heavily leaning towards Brawler because of his incredible speed and potent Neutral+B / Side+B kill moves.