Hello, first thank you for the great plugin, and for providing this update. Once we have it working for our needs, we will absolutely donate to your project as we do for all of the plugins we use on a consistent basis.
In testing the previous version, we were able to insert the image, and then clear the height/width fields, and as a result the image was able to display responsively without the need for a filter. This is no longer the case with the new version.
With the new version, there is the ability to assign WP sizes (great) and also Custom (also great) - but clearing the custom height/width fields no longer provides the responsive effect - nor can we assign percentage or 'auto' as an option. As a result, the image has no ability to be responsive through the core options.
Of course, using Firebug, simply applying 'max-width' and height:auto immediately resolves this and the image responds. I understand from your documentation we could apply a filter - but it would be a great help if you could show an example of this?
But also, it would seem having this ability through the core settings (or, allowing it work as the previous version did) would be a big plus given the growing number of users utilizing responsive designs.
Again, thanks much for all your efforts.