If there was only one change that could be implemented in the new design, my wish would be to include more information on the initial 'hovering'.
Instead of just title and author, it would be so helpful to have title, series name and number and author.
Available copies and number of patrons on hold list is probably asking too much, but would also be welcome. Also a listing of available formats.
Having any or all of the above 'at a glance' would definitely make browsing NextGen more enjoyable than it is now.