what is the advantages you're farming millions per hours in TH7?
if you can farm 1.5 millions per hours and you raid just 4 hours a day, you will get 6million / day... which translate to 30 purple walls per day
well... you will finish those walls in 6 days ... but you still need months to max the TH7
the game will be very boring and that's what I feel when I'm TH7... I finished my walls in 1 week and then waited doing nothing for almost a month well it's the saddest moments on CoC.
I can't farm because my storage is always full.
So, I just watch TH8 rob me everyday, and donate lv.4 archers for my clanmates... lol...

