Totally agree about the keys. You have to always weigh up the pros and cons.
The fact that they offer over 6% on GBP is pretty inviting though compared to the banks!
I have been watching a lot of their AMAs and they seem very professional and are in the process of obtaining banking licenses in various jurisdictions.
But still there's always a risk. If they obtain a banking license in the UK then they may fall under the government's compensation scheme. That would be sweet!