It was in 2011 that Thomas Voegtlin launched Electrum wallet and since then various developers has worked to improve it. This wallet has some features that can only be understood by those who have been dealing with cryptos and have been using other wallets before.
It is open-source and the code was written with python which is very easier and shorter to review. With electrum wallet you can decide how much you want to pay for a transaction, and if you see that it is not faster like you want you can increase the fee.
However, it is only bitcoin that you can store on this wallet. With Electrum wallet it is possible to manage the address or contact that you are using on regular basis by storing them somewhere for easy access. You can also connect it with hardware wallet. It has good support from bitcoin community.
But as good as electrum wallet is, it is not suitable for new comers, because there is no much information about how to use the features in the wallet.