hi
FRANCE(sorry for my bad english)
samsung TAB 7 
nexstar evolution wit or without  wedge
canon eos 750D or eos 70D
all work fine (connect , guiding etc ....)
but .....
fot the same target
1==> with asiair connect
canon (preview and more with ....focus !!!! throug asiair) is awful too worst
and i do the same (exactly the same ) with backyard eos  via usb
or eos utility via usb or ....
Android dslr controler via USB (eos ===samsung tab)
the result is perfect 
why throug asiair its so badddd ????
the apps itself with zwo 224 (main) its very good 
but i have tried with other device
as samsung tab 10 , s6  
same result and can't use .....the "focus screen")
great thanks