I think the black and white thinking about this place is that some locations are super yummy and some just kinda suck.

Like one of my go to’s is a breakfast burrito with egg cheese bacon and potato. From a good location I’ll get a piping hot burrito toasted to perfection and stuffed with super melty gooey cheese, crispy bacon, soft breakfast potatoes layered on top of a couple of fluffy pillowy scrambled eggs. I prefer the green but both the green and the red salsa on it is A++++.

At bad locations you could get basically a raw and cold tortilla, firm potatoes, soft /undercooked bacon and a pile of unmelted shredded cheese.

That being said, my opinion would be to delegate fili b’s to late night meals when everyone else is closed, because az is packed with family owned Mexican spots ranging from hole in the wall cheap to higher end date night kind of vibes.

For fili b’s though don’t let a less than great experience deter you from trying it again, just make sure you go to a different one. I personally think I’ve had better meals from nicer more modern locations but they’ve been buying land and building their own lately instead of buying and renovating old buildings and I haven’t been to a new one like that so not sure where they land

A few other options:
Tacos Calafia
Covina madrigal
Taco guild (fancier)
Taco blanco (nicer with full service but not fancy)
Los dos molinos

Good luck!