I gave it a quick try, the stages are well balanced. At full capacity (first stage expended) it can launch 70 to 75 tons to LEO. However I tried to land the first stage, the flight itself goes well, but once you deploy the landing legs the first stage becomes terribly unstable, and it's hard to land. I'm not the best at this though.
With a decent payload the TWR is rather correct to me (1.5 with 40 tons of payload), though you could potentially lift a bit more by adding fuel to both stages.