When is a good time to upgrade the townhall 9 to townhall 10

I'm not sure how the loot would be, how much harder it would be to upgrade the heroes and walls. I'm townhall 9 have already maxed everything instead of the walls and heroes. My Walls are level 9 and I have 12 level 10 walls, my heroes are level 15. I wanted first to make just all lv 9 walls, then I wanted to make half of the lv 10 walls and now I just want to make walls and heroes until my heroes reach lv 20 and the upgarde the townhall. Did someone has experience from townhall 10, what have you done?

Personally I have no experience of th10 but I can still recommend what I would do and what's best.
Personally I'm going to max walls and heroes as I am war orientated, this is going to cost me lab time and some builder time but I think it's worth it as it will benefit me at th10 as well.
As a minimum I would get 20/20 heroes and just do as many lavas as you can in that time. 20/20 heroes is the minimum you are going to need to take down strong th10s in war, or farming th10s.

It's all up to you, play the game how you want. I'm probably going to push to maxed lab and at least 15/15 heroes, if not 20/20, and then I'm moving up regardless of where my walls are. I'm getting ready for some new defenses and base designs.

I think as a lot of people have already posted on this part of the forums, TH9 to TH10 is a lot trickier than TH8 to TH9. I've seen a lot of rushed TH10s and I have one in my clan that just sucks in wars, I think troops should probably be maxed at the very least. Check Morgauth's post out on here for rushing tips, idk if you're a rusher or not, from your post looks like you're pretty dang good at close to max.

Your walls and heroes are better than mine so i think you ready to go th10. Just focus upgrading your troops when you reach th10 and build those additional defenses. Inferno tower is a must because its what TH10 differs from any other TH level. Stay on crystal 3-2 to farm, believe me, its easy to farm using max troops at th10. I've attached some of pictures to encourage you that what im saying is true. I upgraded my defenses one at a time, i started with my area damage towers (wizard towers and mortars) and teslas cause your enemies dont know whats in store for them when they attack you and thinking your defenses are just max TH9. Good Luck and have fun at TH10.

Want to post some Pictures but I don't know how lol

Check out my sig if you want, loot isnt bad. Im currently farming the league bonus no problem in mII-I

I will upgrade my heroes unti they reach both level 20 and then start my townhall, and in the laboratory I have already maxend every troop except the Valkyrie, she is still level 1 xD my king is upgrading to level 16 my queen is level15 and I think I should make walls to level 10 until the heros reach level 20. I just hope Supercell allow us to us our heroes during the upgrade because every level takes 1 week :(

Just get as much maxed as possible