I'd say th9 is more of a stalling point then anything. 30 weeks or so at least just to upgrade your heros if you don't gem and that's if don't take breaks for war.. which is VERY hard not to do because war is just a lot of fun at th9. People just stick around 9 cause it's was and is a sweet spot.. it's not that we aren't progressing forward it's that you get enjoy other aspects of the game besides grinding and the things you need to grind for take months not weeks (max walls and heros). The desire to rush sorta vanishes for a lot of people at th9 because up until the warden you get access to everything.

