ExB's responsive design doesn't work well when you use an experience across different devices that have different screen resolutions and text/app size preferences (desktop/notebook).
An experience built with a resolution of 1440x900px loses lots of the configured adjustments and aligments. You open the app on a device with a lower screen resolution or different text/app size preferences and you get overlapping widgets and lots of scroll bars. It makes the experience look like "work in progress". % instead of px and other settings don't make a change. Unfortunately the preview function doesn't help and is even inaccurate in some cases (preview different to live view).
My suggestion: ExB should get better responsive design/rendering capabilities and more preview options to increase usability and satisfaction.