Kel and Tobin are known to cause headaches for the OL (particularly in SoB, from what I hear), Jonas's ability sounds cool but is really only sometimes useful. Nara's ability is the only solid one of the bunch, and she's also conveniently the easiest one to get ("easy" being a relative term, you understand.)
I've read about Tobin in campaign mode; I still have to start an advanced campaign, but I see the point of being able to one-shot the Level/Dungeon leaders from distance when at Silver/Gold Level. He proved to be only average on Vanilla Quests, where his poor Speed doesn't help a lot with huge maps.
I suppose Kel won't be any better, especially if you read her ability as working ALWAYS, including spawning LoS. Combined with Shadowcloak immunity on Islands is enough for any SoB OL to give up.
Jonas and Nara look more balanced. Jonas has the chance to get around the Undying ability and he's immune to Crushing Blow, besides being very quick. 0 Armour is a little bit strange for a Hero COVERED in full plate, but perhaps that is just bronze with little protective function. I think he makes up for a decent Runner in a campaign group. Nara looks like a balanced Melee Hero, but I never saw her in play.
Frankly, above all else I hope for 2e, the thing I'd like most is to NOT see any more promos figs. All they manage to accomplish is to make an inordinately large number of people feel left out because they can't get a small set of ultimately not-so-great figures.
My only chance to get those figures was the German version, since I live in Italy and have easy access to that market. I like the minis and the Runebound cards, but I admit that some of them feel very imbalanced in their Descent incarnation. I hope there won't be promo-elements like these in future Descent editions. Missing a card, e.g. a bonus Treasure Item, is something I can tolerate as a game fan and collector. Missing a miniature that expands 3 different games (I don't own Runewars, but who knows...) is simply... frustrating. Please don't release such promo figs again, they will become an headache for most fans.