So, I ended up buying the Rise of the Tomb Raider season pass from GameStop the other day when it was on sale... I was going to ignore it, I figured it was going to be over priced even at the sale price (which was $8.99), but one of the guys I do regional pricing wanted a copy (which ended up being a few copies) but we didn't get into many transactions as codes weren't showing up quickly... Long story short. I ended up with a spare as I wanted to see if a different address/username would work but it hung too. Truth be told I should have taken my quarter profit and ran.
No spoiler review of the bulk of it... (Baba Yaga.)
First, its sort of jarringly added to one of the large open area that you come across fairly early in the game. I say jarringly as it becomes available when you get a piece of gear... but the main story line says you might want to hurry to the next area (of course you don't really need to but it makes sense to do so). You also have to pass the starting area for the DLC for the next story area so you might end up triggering it rather you want to or not. Also its map markers are in a reddish color that dominates the yellow the main story follows. (Its just really annoying.) Lastly, if you do the DLC first as I did so you end up in the same location as the main story has you going and your getting messages from two different people for two different missions fairly close to back to back. So as I said its really jarring... Why it doesn't pop up notification after the main story takes you to that area I don't know.
The region you go to does have an optional challenge area, like the other ones I've seen so far its really solid but since the DLC description makes no mention of it I believe it to be the base game. The story for the DLC leads to a very predictable conclusion and one that doesn't make much sense. The DLC also includes resource gather (though not a huge amount) a fair amount of back tracking (thank god for fast travel), and one of the worst boss battles I've seen in a long time... It just overstays its welcome far too freaking long... Especially, when you already know how its all going to end. (Some of which isn't explained.)
The good... One puzzle area really stands, like early Tomb Raider games good (but not later in the game were the shit is so cryptic you needed a strategy guide to finish it), so that was really nice. I was able to figure it out without youtube but it did take me some time. (And it was logical, I wouldn't be shocked if it just clicked with some and they roll right through it.) I would complain about something else but it seems spoilerish, even on a small level, so I'll just leave it be. (But, wow, I'm left with some really freaking annoying questions that I'll never get answered.)
tl:dr Baba Yaga is bad. Its the bulk of the Season Pass (4 DLC outfits, some awesome looking stuff but still and survival mode make up the rest of the season pass) so its just not recommended. (Maybe at 5 bucks for the season pass? Maybe...?)