Depends on how invested you were in XIV before your sub lapsed. Surprisingly (or unsurprisingly?) Things hadn't changed too much since HW launched and not much is changing with 3.15 either. If you were the type who stayed up to date on gear and content, it's the same game as 6 months ago. If you're the type that believes leveling everything to 60 is "content" and you only have 1-3 60s, you still have plenty to do and some new ways to gear up those 60s.
Otherwise, it's the same game you left. They added a mini game to Gold Saucer that got abanonded after a week, some new dances..a few new hairstyles..more Mogstation purchases. And yeah, since the Heavensward Patch you're still going to be hanging in Idlyshire if you do have a reason to go there (Tomes/Law gear stuff like at launch.)
3.2 is when some things change (fairly minor when you think about it) since you'll be able to LIGHTLY meld raid gear and they're changing the overmeld spec which is probably the biggest draw, unless you like this game's PvP, as 3.2 is designated the "PvP overhaul patch." 3.1 only added like..4? Story quests..probably the shortest amount added ever, so if you care for the storyline, you'll get caught up insanely quickly.
So in 6 months time, given the type of game this is, nothing changed too much and depending on your server, based on Official Forums..it seems the population is thinning. So if you played on Gilgamesh or Balmung or Lamia it'd be business as usual.
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