Hi,
as also reported in this post on April 27th
http://www.swiftideas.com/forums/topic/image-banner-in-full-size-row-cuts-down-resolution/
the quality/resolution (NOT frontend size) of the source image is cut down to max 1024px width instead of being full quality/resolution as it should be (checked in the source code with chrome inspector).
I guess the image should be sourced from the full size original picture and not the reduced ‘large’ 1024px one.
In the linked post Kyle offered a temporary solution by manually editing the Swift Framework plugin files, which unfortunately is not very convenient.
$img_object = wp_get_attachment_image_src( $image, 'full' );
For the moment I gave up on this and used a regular image asset, which works fine at full quality source with the same options.
If you could forward this to the development team for a quick check it would be great.
Thanks for your help.