I loved both Dead Islands, so there was no doubt that I would enjoy DL. So far, I am loving it. A lot of content, I've been playing it since launch and am just at 50%.
Parkour is done very well, a great improvement from DI, and even when I leveled up to unlock the grappling hook, I rarely use it as I got very skilled in climbing and running. I love the weapons, upgrades, fights and avoiding fighting as well. I strongly recommend this game to everybody.
As your comparisons to those two games, I love Far Cry, so I am glad that they have something in common. Jim Sterling called it Far Cry with zombies but gave it 5/10. I love that this game is Far Cry with zombies, it just increases the score in my book.
You also compare it to TLOU, but I think it's nothing like it, and I love that as well, as TLOU was for me a very lacking game in the gameplay department, and it was one of the most boring games I played recently. DL is much more fun, has better mobility, better fights, stealth is done very well once you unlock the silent kill skill. And one thing I loved in both DI and DL is the depth of crafting, with so many different items to collect and combine. TLOU's crafting and leveling up was so painfully generic and simplistic, it was one of my major gripes.
Again, buy and play DL, it is so much fun that will last you for a long time.