Houzez - Real Estate WordPress Theme
IDX integration mean theme work good with third party IDX plugins and will not crash or stop these plugins functionality if someone will use it. Furthermore, the use of an IDX system is optional and it is not necessary for the functioning of the theme.
About user interface: It’s impossible to have the same UI for IDX plugins as Houzez default because IDX plugins providers use an iframe which not allow changing any HMTL or CSS code, also impossible to overwrite their HTML to make same GUI like Houzez default.
About searches. Theme default searches never work with IDX nor it is possible because theme searched search data from the WordPress database, it is not possible to search and get data from third party IDX provider database.
Using an IDX system is not free and required a monthly subscription with an IDX provider.