Class legendaries then:
Bolvar: Crap, you cant keep him in your mulligan and he is a terrible topdeck. You want to ideally be waiting until he is at least 5/7 but the fact you cant simply play him when you want is too bad. So disappointed in this card.
Neptulon: This card is pretty good even with the overload. Looking at the murloc cards, you should get some value or synergy off of them and if you get warleader its awesome. Weirdly enough it seems way too slow for an actual murloc deck though. Still, I like it.
Malorne: I think this is okay, 7 mana for 9/7 isn't very good but the effect is worth the card I feel. Delays fatigue and its another big threat for the opponent each time. Still, its so slow.Ancient of Lore is still a much better 7 drop.
Flame Leviathan: Where is the joke Blizzard? This may be worse than Bolvar, you can wipe your own board, kill yourself with ice block and let the world know what you have in hand. Then when you play it its a war golem albeit a mech. Fucking trash.
Mal'ganis: This card is cool as fuck but not necessarily that strong. 9 mana for 9/7 in stats is crap for starters, the immune ability also isn't too impressive on its own. The Cenarius esque demon buff makes this card auto include in every demon deck though, if you buff 1 demon its worth it. The fact that voidcaller can summon this is also a huge plus. I like it but its so expensive.
Iron Juggernaut: This card is definitely good but the outcry of 'op' is unwarranted. 6 mana for a 6/5 is standard and the mine doesn't stop your opponent from drawing. However the fact that control warrior games nearly always go in the direction of fatigue means the mine has a very good chance of going off at some point. Warrior likes burst damage such as grom, especially to finish the game so I like it. Powerful card. Oh and it's a mech.
Vol'jin: Fucking insane card. You basically remove an enemy minion while getting preferably at least a 5 mana 6/5. If this works like alchemist it should be unsilencable as well. After you swap health you could smite or go for heal dmg with Auchenai. Best of the lot in my opinion.
Gahz'rilla: Been plenty of discussion on him already and yeah he's simply good. Especially now we have steamwheedle sniper etc to activate him. Does need to live a turn though.
Gallywix: Don't really know how to evaluate this, especially since Auctioneer just got nerfed miracle is even more fucked now. Anyway 6 mana for a 5/8 body is pretty good so you're probably going to get at least one spell out of him. So im going to say hes probably decent however I think Troggzor is the better anti spell minion.