Coming from a near max TH10, I disagree with all the posts regarding easier hero upgrades at TH10. While DE might be easier at TH10, it's in no way hard to get at TH9, esp with the new drill capacity increase. The problem with not doing heroes as a TH9, is that you will have alot of work to do at the early stages of TH10. Army camps, lab upgrades and of course defences. That means you wont be focusing on heroes for a while, unless you can farm big amounts of gold/elixir and have time to do DE at the same time. What all of the people that are saying to move up are forgetting is, that heroes are a massive help with farming. Which means that lvl20 heroes will make TH10 far easier than the ones you have on.
So in conclusion, I'd recommend doing heroes untill at least 20, maybe 25 if you have the energy for it. You'll be in a much better position when you hit TH10 that way.
Hope it helps, cheers.
Rock

