Missing constantly, mainly against higher level enemies, and those bosses/enemies that do like nothing but stun you.
It just feels like i'm not losing a random encounter because I was an idiot, i lost it because i was painfully unlucky and missed 10 shots in a row. Especially with guns, that feel like they're super powerful against basic enemies but the moment you fight a boss with them (even one that's multiple levels lower than you, like the Pump-king or Pirate Jug) they become weaker than the Zil gate guards against a grenade. I mean you end up buying a cool little gun that deals enough damage to take out the weaker of the planet's enemies in a single turn if you play your cards right, only to find out that your cool 3 shot on first turn strategy is completely nullified (thus making three perks useless) against some boss that's level 7. Just kind of feels like there's wasted potential.
Ah, ah, and power armor. Mainly the weapons for/exclusive to power armor. i finally get my hands on a set only to find its an arguable side-grade to my current set and the weapon i've been hauling is more garbage than half the stuff over on Tarkus. It just feels like a really big slap in the face, an anticlimax to rival that of - I don't know, orgasm joke here.
That, and - this is gonna make me sound like a fuckin idiot - when something happens and there's really not any explanation for it. Like, i know i should probably tell why these things are happening and it's probably because I'm an idiot, but i've gotten three psychic tentacle beasts with absolutely NO idea how. Like they just come after i go sell some rocks, and it's less 'oh wow a psychic tentacle beast' and more 'wait what a psychic tentacle beast'.