This will not be the popular opinion on this subject.
Max the walls as soon as you can in TH8. it IMO is the wisest decision you can make at TH8, they help you out more than most defensive upgrades in TH8 tbh. Remember Royals are ground troops and walls slow them significantly starting at L8 Skulls. as a TH9 if you start out with 225 Skulls you will be set up much better than one with purple or below walls..trust me.
TH8 is a funnel for collecting resources, but not for protecting them. AQ will tear a TH 8 up, L6 Giants/Barch eat them up easily. there is just not enough defenses; and the ones you do have aren't a high enough level to continuously repel TH9 invaders. (which are the primary target for TH8s)
IMO your best defense is your exposed unprotected TH in a corner! if your loot is low then they 9/10 lower level TH will snipe ya and move on. Same for Royals hit n run. saving your traps Elix and Dark and CC troops.
Don't wait around in TH 8 maxing defenses only to have TH9 come stop ya down. Or should I phrase it I did not wait around.. get on that TH9 train and beat down the TH8s with a AQ and another spell, and 220 troops of up to L6 variety.
Give this thread a read through.
http://forum.supercell.net/showthrea...o-be-a-premmie
on my 2nd acct after I read this thread I was convinced at the lack of TH8 defensive firepower and realized that
Premie TH9 > even Max TH8. there are so many buffs that can be made up for being early 9 if your farming troops are maxed at TH8. Sharonsym aka Yaw has threads on the rush subject too..
soon people will realize like I did, TH6, and TH8 (with the exception of Skull walls and L5 farming troops, maybe A/Defs and Teslas to max) while good loot stops, are VERY POOR defensive stops and will get PWNED regularly by the TH higher. and rushing to TH7, and TH9 at their expense is a good move if you plan to stop and max those THs.. Max 7 and Max 9 is the best THs in the game to max before TH 10. (TH6 has 1 A/def! rushing to TH7 doubles this and you get access to 200 camps, dragons~4th barrax, Dark Rax, and a 3rd spell, whats not to like?) get the walls at TH6 n TH8 and move on..
again not the popular answer, but there is a reason TH8s are constantly throwing up complaint threads on here. and its because TH8 for all its earning prowess, cannot hold loot, while TH9 dual X-Bows even L1 greatly improve your defensive outlook over even a Maxed TH8. plus more traps turrets and walls...