The current version of Sammy's flagship model offers 2GB of RAM which is something that is being used on the highest of the high-range models like the LG Optimus G. And the buttonless look is merely the result of years of smartphone evolution. We will probably look back in a few years and laugh at those smartphones sporting 'just' 3GB of RAM and marvel how we got by so well and for so long with such low spec'd models.
source: SamMobile via Android Authority
UPDATE: It should be pointed out that despite the sticker reading Gb, the source says that it does stand for GigaByte, not GigaBit. The stickers are, of course, for internal use only!