Spent more than 1000 hours in Destiny, absolutely loved TTK but was really bored by February. Came back with RoI, finished every quest, collected all available exotics, starter ro grind strikes for light... And just can't continue.
TTK was amazing because of couple new strikes, story missions, new subclasses, fun weapons (Hung Jury FTW). Rise of Iron doesn't do anything. The only fun activity is Forge but you should be very lucky to play it with 5-6 other people and not run out of SIVA offerings.
New strike is not as fun as Alak-Hul was for example. It's just invincible Phogoth and a random dude. Updated Sepiks is almost an unsult to the players, "new content" with almost same stages and bosses.
And after you finish all quest you grind useless lvl320 strikes for your book or grind heroic strikes all of which you already played for two years... I would rate it 5/10 or even lower. Can't wait for Destiny 2.