Where to keep the coins, Windows wallet or Exchange/online?

Hello,

I want to get some suggestion, what or where is the best place to keep the coins?

I keep it in a web wallet which is not as safe as windows wallet but then I am too lazy to sync entire blockchain. Jaxx and cryptonator are two good options.

How is Cryptonator compared to Poloniex? ...regarding fees. I'm planning to switch from polo

Pls, compare yourself.
Poloniex fee - https://m.poloniex.com/fees/
Cryptonator fee - https://www.cryptonator.com/fees