It's pretty good for the money, the fan is crap but you can run it without it, or replace with a better one. I wasn't keen on the case, cheap and flimsy feeling but did the job.
Taking apart the stack was awful, I felt it was going to break or bend the pins each time. If you're just gonna stick it next to a tv and play though then you'll be fine.
I just found mister isn't for me, I don't seem to notice the lag in software emulation like some people do. I don't have a crt and wasn't impressed with how it looked on a flat screen tv.
If I want another TV based system I prefer something like Batocera on a cheap mini pc with a nice interface, save states and shaders which i had a while back before buying a bunch of handhelds. You could even get a refurb of a little HP machine from a few years ago for under a ton. These are readily available and would emulate later system past N64.
Mister is impressive, things like the old 8bit or 486 core are very cool. But just think about the systems you want to play, how you play and what's important to you before buying. Or buy from AliExpress so can return it easily