Has anyone used them ? The new rules seem good on paper but I didn't have the chance to test them yet ? Also, what about the outcast bonus? Does it need a rework ?

Never Quit: Outcast characters count their Toughness bonus as one higher when determining the results of Fatigue."

I think it does but I will need to test it first. Maybe make it apply to all characteristics ?

I've tested them a bit, but my players haven't yet accumulated enough Fatigue in one session to be hampered by it. I like the new system so much more than the old one but I haven't tested it a whole lot. I've taken to giving out small amounts of Fatigue for minor injuries in narrative time -- for example, a player failed his Athletics test to climb fairly badly, so he took a rough fall and gained some Fatigue rather than being seriously injured.

I noticed the Outcast thing too. Maybe they could count all their characteristic bonuses as one higher when determining whether or not a given characteristic is Fatigued?