Is there meaningful PVP in the game ? Something persistent and with a good amount of player involved. Or is it all just pew-pew, spawn-kill, griefing and server-hopping ?
The game is nowhere near stable enough to handle large scale PvP at all, even 1v1 battles with medium sized ships lag it up (at least, last I checked).
As for what PvP is like - well, there's basically 3 kinds of PvP servers:
1. Limited sized worlds, typically around 50km^3, with centered asteroids. PvP on these servers is mostly eating newbies and raiding bases while the owner is offline. These servers are actually very rare now that planets have come out.
2. Unlimited worlds, with or without planets. If you build on a planet (or near the center if there is no planet) you are going to find your base raided while you're offline. Everyone else builds a jumpdrive ASAP and fucks off 10000km away where it's realistically impossible to find you (no radar or anything without mods) and there's basically no PvP at all. This is sort of the "default" server, unless they specify no PvP is allowed (which can't be enforced)
3. Creative mode, people join up and paste their ships in and blow each other up for fun. This is probably the only "real" PvP where you've got two people in combat ships fighting each other that you will actually see.
Space engineers is just not designed for PvP
at all. There's nothing to fight over, near-infinite amounts of space to hide in, and no reason to ever interact with other players. Don't buy it expecting a PvP or Faction v Faction game.
Meaningful PVP occurs when you have a successful asteroid mining base, and a ship at least 100 units long. After that, most scrubs wont just bum-rush you, and youll be able to output enough firepower to do more than just annoy your enemy.
Just....no.
If someone finds your asteroid mining base or 100 block long ship, no matter how much firepower you put on it, it's dead. They can sit 801m away and snipe the turrets off while you're offline and there's nothing you can do about it. The recent patch that added spread to weapons didn't change anything, it just uses more ammo now.