Not a major lag, but some moment may lag.

well, i am using 2 o1, one on 10c one on 10e
angry bird is good when turn off wifi. some stage it lag, for the begining, after that is good and smooth. no stage will lag til cannot be play, and certainly, never have slideshow kiind of lag..
using stock sd card too..

tried back 1-20/21 just now.
1-20 smooth after <15 sec of waiting, then lag free
1-21 smooth after <30 sec of waiting, with minimal lag when bricks after collapsing, but still good to play.
on stock rom 10e, stock sd card.

setting>about phone
u can see at the bottom.
btw, wat's ur angry version? latest one can turn off backgroud for better performance.
my test was done without turning background off, so suppose better performance if u turn it down.

mmm....generally task killer is useless if not will harm our phone, dont cant use our pc knowledge on android system...
full utilize of ram actually makes our phone faster.
cpu on the other hand, need to monitor to assure no misbehave apps eat up too much cpu power.
uninstall ur task killer and install watchdog lite instead..
check this article
http://lifehacker.com/#!5650894/androi...ouldnt-use-them
and credit to whoever share this out previously, i cant recall who he is, much thanks and i learned a lot!

nb: for antivirus, i use lookout, it works fine for me.
it scan everything we installed, and it scans them fast~

actually, u can do watever u want while charging also wat...

Guys as promised, below are the picture of Epikcase for O1.
I'm using the clear color (White)
You can get it from AskarPerang in LYN