Ok,
my question is, how much coins you keep in wallet and how much on exchanges?
Is it like 50/50 or more like 90/10?
In depens what you are doing with your coins and how much do you have.
If you aren't trading and just holding bitcoins, it would be best to keep ALL coins in a wallet. If you are trading, keep on exchange amount of bitcoins, which would be enough to trade.
I'm not serious trader, so I'm only keeping less than 10% of my bitcoins.