I make captioned, ordered galleries everyday as part of my visual record flow. I also make them for/with friends and clients working on portfolio sites. WordPress gallery flow has always lacked access to full-width, comfortably viewable images. Calypso continues this lack and also removes access to uncropped images from gallery flow. Lack of uncropped, full-width images in gallery flow along with broken gallery upload on iOS devices and disrespect for upload order hamper gallery flow for me to the extent that I still must use wp-admin for galleries on all devices. For details, see The impact of upload ordering and cropped thumbnails on captioned gallery flow.
Fixing the following would ease my gallery flow and prevent bailing to wp-admin. These impact me every day. One of them is a blocker to creating galleries on iOS.
Editor, Media: Gallery flow lacks access to uncropped, full-width images
Editor: Media: Stuck scrolling in gallery preview