I just downloaded both. Mycelium seems a bit easier to use and more user friendly. Electrum seemed a little laggy/unresponsive as well. Took a while of me tapping the password input box to confirm my password before it popped up to allow me to do so.
When logging into mycelium on another device is there no log in details? It didn't seem to give me any so do I just log in with my seed?
What do you mean by log in? MyCelium is a mobile wallet and there isn't any way for you to log in using an email and password. Your private keys are recovered using the seed. If you need extra security, you can add a passcode to protect anyone from accessing your MyCelium wallet. The seed won't be protected using any pass code.