The S4 looks to be a solid update. Faster processors, slightly bigger screen, significantly more battery power, 1080p HD, which is a GREAT spec. The 13/2 megapixel cameras are a nice upgrade.
I like the ability to add memory without paying $100 or $200 extra; as well as the ability to swap out the battery if so inclined.
The customizability of android appears to be a nice feature.
OTOH, the plastic doesn't appeal to me, and I still distrust the android os. I reckon it's similar to windoze. A number of the whiz bang features don't seem to be daily or even regular use features either, and the eye tracking just seems creepy.
If I get an android device, it would be the note 3 or a later version. I could stow it in a jacket pocket much of the time, and it would probably fit in my back pocket as well. Chicks wear skinny jeans all the time and manage to fit their phone in their pockets al the time, so I think I can manage with my less than skin tight jeans.