I really like the glider part of it, floating around looking for secrets. The stories that play out around the outposts seem interesting and at least for now attracts a quite large pool of players. I found all the stuff, upgrades and mastery points and what-have-we-here really confusing the first day, but I am slowly getting the hang of it and enjoying it, and that journey is worth my money any day. I love the abilities you learn through masteteries and the way specializations alters your playstyle (fear my mountain riding ele).
On the negative side - and this should be taken with a grain of salt since I have only played four times - the overarching story seems kinda lame in the trying-too-hard-to-be-epic kind of way and with too many words that aren't that interesting to read or hear. The quality of the voice over is also a bit low, dragging the story down.
I do not know why, but to me it seems that Anet is incapable of writing large ongoing interesting stories, while all the small stories that play out around renown hearts and now outposts seem intense and immersive. Maybe it is because they alow the smaller stories to be quirky and have that funny or odd side to them, while the large stories always are something along the lines of "we have to save the world from the largest threat known to mankind"-blabbering.
TLDR; Buy it. Great content that will keep you playing. Just take less notice of the story (at least the part you experience within the first hours).
Logged into my seldom played necro yesterday, chose the blood specialisation and the trait to put vampiric on foe when bleeds are above 4 and did nothing but siphoning and bleeding enemies left and right for an hour with just the scepter. From that 1½ hour of experience this seems a little like somewhat a new game kinda (to me at least).