Here's my initial review of the new Survivor mode.
It's rough! To me, that's good thing. A few weeks after starting my first game on release day, I moved it to the old Survivor mode, as the game was very easy on the default setting. I got about 2/3 of the way though the story, constantly being distracted by crafting towns, shops, and growing my economy, after already being strong as a superhero. The old Survivor was not much tougher at this point.
I image it was much more challenging early in the game, so I was kind of pumped to hear about the new Survivor mode. I loved it in New Vegas. I (sometimes) miss the old days of when games were challenging.
The new Survivor mode brings it. I started a new character. After a couple of rough starts, I decided to avoid Concord after being slapped down a few times. At this point, I probably have about 10 hours in, and FINALLY got through Concord after 10 attempts. I *IS* about smart strategy now. Being Rambo will get you killed. I had to plot and plan, and it paid off. And they have now added the strategy I was looking for!
This might be a spoiler, but I think it's been said in the all the previews. You WILL need a lot of antibiotics. Bit by a mole rat or hit by a bloatfly? You'll need them. Chemist as soon as possible. Seriously. Base your build towards this. I will, if I start another new character.
For example, I was running around, after finishing Concord, I had previously contracted an infection and let it ride for a long time. I didn't have an ABs, so I kept on. I probably had it for a few in-game days. It got worse and worse, until it was taking 1/3 of my HP every few minutes. My build was screwed to where I couldn't craft any for at least 2 more levels. If the infection got any worse, I would be out of stimpacks and food and I would die. And I mean, permadeath, as I was semi-remote in my last save, and wouldn't be able to go on. I was lucky enough to be able to buy some from the only vendor who might have some. It's rare to have them for sale, at least so far. After all these hours put in, I was truly facing death. My day (life!) was saved.
It was incredibly suspenseful. The actual relief I felt was amazing!
If you're looking for a challenge, and it's not for everyone, it's good time!