Who says you have to sacrifice design features? Your watched that video with the coating right? Go to their website, you'll see they can do the note 3 right now.I think the folks that want the feature bad enough to sacrifice design elements are in the vast minority, at this point. I also believe that very few people purchased the S5 because it has water-resistance. For instance, if the S5 didn't have water-resistance yet the S5 Active did I do not believe there would be noticeably less S5 sales and more noticeably more S5 Active sales.
I believe Samsung wouldn't have made the S5 waterproof if they didn't think people wanted it. You'll see the notes waterproof eventually.