Figured I'd throw my initial thoughts in as well:
Technical Points:
Lack of 21:9 support really does smack of laziness and it's a big sticking point for me. Thankfully my monitor supports automatic scaling so it's at least centralised, but I'm not impressed at having 3" black bars either side of the screen.
Very first impression of controls? Menu navigation is clunky as hell, with non-standard and un-intuitive key bindings. "Tab" to go back and "Space" to select? What's wrong with the standard "Esc" and "Enter" which every other PC game uses?, also other key bindings such as using the same key for melee and grenade? Then there's the stupid wheel for changing weapon, why can't I use my mouse wheel normally?!
Why can't I bind weapons using hotkeys, I have to favourite them in the correct order, or go through the stupid wheel to change the positions!
The trading menu is really slow as well, I really like the functionality, e.g. setting prices and quantity, but the implementation is terrible, it's so awkward to use with way too many button presses.
What's with having to access the Map first to get to the menu? That's just moronic.
Clearly the UI has been designed 100% for controllers, and at the last minute someone has realised most PC players actually use a mouse and keyboard and simply mapped the same functions to some arbitrary keys, rather than thinking about how it's actually going to work.
I've also encountered various glitches with enemies suddenly appearing, items showing up which don't actually exist in the world, shots not registering (my aiming may be bad, but a point-blank shotgun blast to the torso is pretty hard to mess up!).
Gameplay:
Despite the above, I really want to like this game. As a big fan of Fallout 3 and 4, it's definitely along the lines of more of the same, but it just seems to be missing something. Maybe it's because by their nature multiplayer games tend to lack the gravitas of single player, but while we were playing (me plus 2 friends) it didn't have that immersiveness that the previous games have.
The world feels empty. Really empty. It's great being able to boast about a huge map, but if 90% of that consists of a quarter mile of empty forest followed by an isolated house and repeat, then what's the point? It's not content, it's just filler!
We played for about 6 hours, and must have explored about 15-20% of the map, which doesn't bode well for longevity, I can see the end game just being a case of grinding to get the plans for a different kind of light or painting for your base....
Speaking of bases - what's the point in capturing the existing ones? We claimed a junkyard and built a few extractors for concrete & titanium, but as far as we could tell, anyone can take the generated resources anyway, so why bother to claim the base and use your own resources to build extractors when you can just take them from someone else's?
We also didn't really find much in the way of appropriate challenge; all the enemies we encountered were pretty easy 1-2 shot kills, except for a lvl 50 scorch beast which we could barely even scratch.
It's pretty obvious why the beta is in such short, restricted timeslots. I don't buy the nonsense about it being to concentrate the number of players for a second. I think it's because if it was online for the full 14 days, it would become clear very quickly that there's a severe lack of content.
I realise all of the above is pretty negative, which is a shame. We did have fun playing, but there are just so many little niggles, which unfortunately aren't really related to the fact it's a beta (e.g. I doubt they are going to completely re-do the UI for PC, or add twice as many locations before release), so I'm struggling to justify paying the ridiculous amount they're asking for.
It's clear that they don't want PC players, so to be perfectly honest, I think I'll be happy to give them what they want and cancel my pre-order.