Played a good 6-8 hours today, got most of the quests done on one character and pushing light 341 (started at 301). I'd give RoI a 6/10 so far, maybe the raid will blow my mind and raise the score but I doubt it.
The setting, atmosphere, etc are all very mediocre. I don't fault bungie, after the epic-ness of the Taken King, where you are hunted by a God who has killed trillions of souls across millions of planets, its hard to get excited about whatever the hell SIVA is supposed to be. The campaign was extremely short and disjointed. There are some cool things, and I haven't even touched PVP yet and I am sure I will really enjoy that for a while.
Its pretty obvious though after 2-3 weeks I'll be bored and quit playing for the most part, which is fine to me. $30 may be a little too high a price for what has been delivered, but I hope they roll out monthly events and stuff until Destiny 2 which makes the price pretty palatable. For anyone who hasn't played Destiny, paying $60 for everything is a fantastic deal.