I'm sorry to say I'm very disappointed and underwhelmed by the new stage .
It's very similar to insane stage except it's a lot harder simply because the enemies take more killing and hit harder. It's doable ok but I don't think the rewards merit the increase in difficulty and time it takes to do it.
I was expecting much better rewards, especially experience wise which I thought would be a minimum of 3000, more gold which should have doubled at least and I thought King Solomon himself would be the last boss.
I also expected there to be a random reward with 3 gold chests dropping in occasionally but if that's been implemented I haven't seen it yet.
All in all it's a major letdown and I'll be sticking to insane stage in future because I can make much more exp and gold, and quicker, on that stage.