I was at first pretty underwhelmed by the Note5, but now I'm quite interested and I think I know what game Samsung is playing. Look at Apple: sealed battery and charge a fortune for storage. They're the biggest company in the world and sell boatloads of overpriced units that people are desperate to buy. So does Samsung either:
A. Chase dwindling sales from people who want removable SD cards and swappable batteries
B. Make their phones as desirable as Apple's products and try to tap into that much, much bigger audience.
Samsung are clearly trying to play Apple at their own game. The Note 5 is basically what the new iPhone 6 Plus is going to be when it's released, but with an SPen. The Note5 looks beautiful but they've not gone overboard with the specs arms race since Apple doesn't exactly overspec their products.
The last S6 was an equivalent product to the iphone 6 in terms of build quality and desirability and the Note5 is this year's iphone 6 plus. You can argue that sales of Samsung's products have been in decline, but their business strategy might take some time to pay off. They are the only Android manufacturer big enough to take Apple on in this game. Whether you like Apple or not, if you go into one of their shops and pick up one of their phones, you can't help but wish more phones were made as well. Samsung now has genuinely competing products and I hope they succeed.
EDIT for myself, I have a Note 2. I was very very close to upgrading to a Note 4 but I didn't because I realised that the Note5 was almost certainly going to be as stunning as the S6. I want a non-Apple product that looks and feels as nice as an Apple product. Peelable plastic backs with faux leather? I don't want, thanks. The Note series are amazing phones only let down by Samsung's attempts to throw everything in there and compromising the look and feel because of it. I am hopeful that the Note 5 will be the device I want. However if it's not available in the UK this year I may well find myself with this year's iphone 6 plus.