I don't normally review DLC's, but Sam's story has enough material in it that it feels warranted.
For those that don't remember Sam is the American that's been following Artyom in the main story. Most of the crew mates talked a lot but were non-descript, so at the very least you can tell Sam apart from his English. After the ending to the main game the DLC sees him leave the crew and attempt to head back home: across the Pacific to California.
Sam travels all the way to eastern Russia, to Vladivostok. Which is actually an interesting city; it's one of, I believe, two cities in the Far East that is majority White. It's odd having a European city in the middle of North Korea and Japan. We find a sub (and its current captain) and that's our ticket across the Pacific. After a few tasks, of course.
The map design and level layout is something like 'Exodus Lite'. Whereas in the main game you usually had a mid-size map that was somewhat open and had main objectives alongside optional vicinities to explore, Exodus' maps usually only have one way of going. With maybe an optional building to explore. Towards the mid-point the map opens up a bit more, but it's still small with linearity to it.
It's as a DLC should be: a smaller experience of the main game crafted just as well.
My only complaint is that you can't save whenever you want. You have to rely on the game auto-saving. So you can go through 30 minutes of play and clear out a facility only to die and have to re-do it all. The way around it is to return to rest locations or areas where the game auto-saves. Example: in the beginning there's a chair facing a lake where you can sit and play a harmonica. Doing so auto-saves. So you'll return here a bit just to initiate the save.
It's a dumb roundabout way of achieving what should be standard. But this never ruined the game for me, since you're never going to be an hour deep into a task. The DLC can be completed in 4 to 8 hours, so you're never losing more than 30 minutes of progress. Still a stupid error though.
Just make sure to rest whenever possible. And pause and check the load screen date and time to ensure the game saved.
That aside I'd give it a 6/10. Nothing amazing but well above average. Makes you wish for an expanded game, which is how a DLC should feel.