Whether it lives up to your expectations or not is completely personal and subjective. However with the Destiny 1.5 comments, I'm not sue what people expected. Something like CoD or even Final Fantasy, they're iterations or stand alone but games like Destiny that are story driven the sequels are always more like DLC packs. So for me, it isn't a question of is Destiny 2 going to be different to Destiny 1 because when it comes to mechanics, lore, premise etc. that isn't what I want. I want Destiny 1 with a few tweaks, more of a story like the later DLC's than the vanilla game and, as it costs the same as a new game, a huge chunk of content.
Maybe Destiny Chapter 2 is a better name for it being that is what it is rather than a 'new' game.