Well, the Network need people running full Nodes (Bitcoin-QT). Without them there is no Bitcoin.
For example, all mobile Wallets rely fully on full Nodes to work.
So, if you have the resources available and want to support the Network I encourage you to use QT.
From a User perspective there speaks nothing against electrum and for systems with low resources (RAM, HD-Space, Bandwith) it is much better.
Using Electrum, You cannot make a transaction to multiple addresses.
Apart from that, Electrum is very good and user-friendly.