Electrum has changed their wallet format from 2.6 to 2.7 and it is not backwards compatible.

What do you guys know about this? Is it an improvement? If so how?

I have noticed that the new 2.7 version of Electrum no longer seems to have "watching-only wallets". When you make a new wallet you can only choose "watch bitcoin addresses". Then you have to enter a list of bitcoin addresses to watch. This is nothing like entering a public master key that one used to do in the past. So why do they no longer have watching only wallets? Are they insecure? Any news about this?