Is Electrum safer than Poloniex?
Yes. Poloniex is an online exchange, not a wallet. This means you don't have control over the private keys that belong to your bitcoins. This means that if the exchange gets hacked, runs with your money or something else happens your shit out of luck.
I have heard a lot about these two wallets, but there are people who complain about one or the other. I definitely choose Electrum because of that security. I have never been disappointed and feel safe and secure. I recommend to everyone.
Blockchain would be still safe choice as web wallet electrum is desktop wallet so i think if you are looking for a web wallet blockchain could be safe..
And coinbase i think can be trusted because they are legal business so they can not run our wallet.. but i stop using their service because of delay responds when having an issue with their wallet..
So the best wallet i can suggest for now is blockchain with their good service and good support..
Electrum is good for desktop user and also don't experience any issue about using it but this is only good for saving all your funds for a long time and blockchain or coinbase is for daily use..
