I love the new Basic Filter option and it makes writing filters easy/self-expanatory for new users and helps with functions like isnull(). However, I'm almost always writing what are now called 'Custom Filters' and it takes two clicks to do this.
From a User Experience perspective it would be great if you could click in the expression box to write the filter rather than having to check the customer filter check box, or start by creating a basic filter and then make it more complex using the custom filter box without having to check the tick box.
Following on from this and something that is probably a lot harder to implement - But with the new basic filter, it would be great to have a list of available fields populate the options to filter by - Similar to the option that you get in Calgary. E.g Country == and then the drop down list would contain whatever is available in the data (e.g. Spain, UK, USA, Etc...)