I thought it was fine.
I'm not a massive fan of the games, and only really got into the 3rd and finished that. This finally made me grab 4, but I'm struggling with it, I'm just sick of open world stuff.
However, this TV show was fun, had some good dialogue and kept the story lines concise and had excellent pacing. Good sound and the visuals had a spot on grimey look while also retaining that "video-game" aesthetic.
It didn't however get anywhere near TLoU in terms of storytelling, tension or chemistry between characters. That show was near perfect as an adaptation from game to screen. Fallout just leaned a little too much on the games and could have gone darker and bleaker in places, there never seemed to be any real peril or risk for the main characters.
On a normal rating system I'd give it a solid 6/10 and will definitely be watching the second season.