I'm a fan of Stoic. Conceptually, it's very heroic to be able to survive that one giant explosion or a fall from space to the ground or whatever. Heck if I were playing a character with it, just having it would encourage me to take stupid risks (at least until I'd used it for the day). "Don't worry, I'll be the one to jump out of the plane without a parachute and catch them on the way down." Who doesn't want to be the guy who stares down the dragon, takes the swipe that sends them flying across the room...and gets up again. That's the stuff of coolness.
Hmm, I'm not sure I'd like giving Stoic that much power. If a stiff upper lip can undermine instant death effects, it risks breaking suspension of disbelief. I'd
hope for a GM to say "No your stoicism can't help you survive being vaporized by that battleship's lasers. Make a new character." Of course, they might handwave it a bit. "Sure, you survived falling from that airliner 30000 ft with no parachute. You have one HP for the moment. But you also have every negative condition at once. Oops, I guess that means bleeding kills you at the start of your turn."
I do think Stoic could be a reasonable choice for very low HP characters, maybe. But that's not going to be common, since you need to have a high WIL to qualify for it, and your WIL pool contributes dice to your HP. So unlike Rugged, Stoic has negative synergy with itself.
Anyway, I've updated the first post slightly. I moved Tough-as-Nails into the Always Good category, and added a little more discussion to Alcoholic and Stoic. I've also added a color coded table showing the traits by attribute, which might make it easier to see which ones might be able apply to a given character design (with some attribute tweaks, perhaps). Here's a copy of the new table:
[TABLE="width: 0"]
[TR]
[TD][/TD]
[TD="colspan: 4, align: center"]High Attribute[/TD]
[TD="colspan: 3, align: center"]Low Attribute[/TD]
[/TR]
[TR]
[TD]STR[/TD]
[TD="bgcolor: #ffe599"]massive[/TD]
[TD="bgcolor: #00ffff"]athletic[/TD]
[TD="bgcolor: #ffe599"]brawny[/TD]
[TD][/TD]
[TD="bgcolor: #ffe599"]feeble[/TD]
[TD="bgcolor: #ff9900"]tottering[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]AGI[/TD]
[TD="bgcolor: #00ffff"]nimble[/TD]
[TD="bgcolor: #a4c2f4"]deadeye[/TD]
[TD="bgcolor: #00ff00"]ambidextrous[/TD]
[TD][/TD]
[TD="bgcolor: #ffe599"]clumsy[/TD]
[TD="bgcolor: #ff9900"]lame[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]END[/TD]
[TD="bgcolor: #ffe599"]rugged[/TD]
[TD="bgcolor: #00ff00"]tough-as-nails[/TD]
[TD][/TD]
[TD][/TD]
[TD="bgcolor: #ff9900"]coughing[/TD]
[TD="bgcolor: #ffe599"]asthmatic/anemic
[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]INT[/TD]
[TD="bgcolor: #a4c2f4"]empathetic[/TD]
[TD="bgcolor: #00ff00"]alert[/TD]
[TD][/TD]
[TD][/TD]
[TD="bgcolor: #ffe599"]naive[/TD]
[TD="bgcolor: #a4c2f4"]distracted[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]LOG[/TD]
[TD="bgcolor: #a4c2f4"]brilliant[/TD]
[TD="bgcolor: #00ffff"]erudite[/TD]
[TD][/TD]
[TD][/TD]
[TD="bgcolor: #ff9900"]illiterate[/TD]
[TD="bgcolor: #ff0000"]forgetful[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]WIL[/TD]
[TD="bgcolor: #ffe599"]stoic[/TD]
[TD="bgcolor: #ffe599"]unflappable[/TD]
[TD][/TD]
[TD][/TD]
[TD="bgcolor: #00ffff"]alcoholic[/TD]
[TD="bgcolor: #00ff00"]reckless[/TD]
[TD="bgcolor: #ff0000"]spendthrift[/TD]
[/TR]
[TR]
[TD]CHA[/TD]
[TD="bgcolor: #ffe599"]commanding[/TD]
[TD="bgcolor: #00ffff"]inspiring[/TD]
[TD="bgcolor: #a4c2f4"]suave[/TD]
[TD="bgcolor: #00ff00"]persuasive[/TD]
[TD="bgcolor: #00ffff"]unwashed[/TD]
[TD="bgcolor: #ff0000"]disfigured[/TD]
[TD="bgcolor: #00ffff"]obnoxious[/TD]
[/TR]
[TR]
[TD]REP[/TD]
[TD="bgcolor: #ffe599"]egotistical[/TD]
[TD="bgcolor: #a4c2f4"]well known[/TD]
[TD="bgcolor: #00ffff"]flamboyant[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[/TABLE]
[TABLE="width: 0"]
[TR]
[TD="bgcolor: #00ff00"]Always good[/TD]
[/TR]
[TR]
[TD="bgcolor: #00ffff"]Situationally good[/TD]
[/TR]
[TR]
[TD="bgcolor: #a4c2f4"]Maybe Good, but 1/day[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffe599"]Weak[/TD]
[/TR]
[TR]
[TD="bgcolor: #ff9900"]Severe RP consequences[/TD]
[/TR]
[TR]
[TD="bgcolor: #ff0000"]Always bad[/TD]
[/TR]
[/TABLE]