Nacho's not my favorite character, but I'm down.
He just seems like someone I wouldn't trust even a little bit. He has this ever-present "I'm going to fuck you over" look in his eyes.
Which is funny because he's as close to an 'honest' thief as we have in the series. He tried to bring in Jimmy on a burglary he was planning. He almost gets caught out by Daniel Wormhold (I think that's his name) driving that giant "I am a drug dealer!" hummer. He has to deal with Tuco's insanity. He literally cannot believe that Mike wants to take down Hector out of a personal grudge over a normal reason like money. He screws up Mike's shot as a result.
Dude really just wants to do be a normal criminal, but he's surrounded by insane people.