Basically, the title. I'm finding that the old route of HP T1, HP T2 (assuming no token, of course, but most games you won't see one), buy/HP T3, TT2 on T4 as you HP/buy again just leaves you a hilarious amount behind. You're a good 10-15 health down before you come anywhere near being able to win a single round, AND you're turns behind on tiering up. If you try to speed up tiering up with tier up and HP, you get wrecked by the fact that you have two minions and your opp has five that aren't much smaller than yours, if at all because you're behind on tiers and on buying power.
Really seems like the payoff of eventual stats just isn't worth it with the ridiculous stats others get early-mid.
I still use him like that, but I'd say he is weaker than he used to be on average. Try to not pick C'Thun unless there are 2/5 tribes with token generators in the lobby so that you have a much better chance of getting one for t2. Having mechs in the game also helps your early game as the 2/1 pup is a great early buy.