I once made nachos with pork loin for a special visit from my nephew, that I rarely have the privilege of seeing because he's active military, along with his also active military girlfriend. They weren't tacos per se, but the meat treatment could be used very effectively for tacos.
I took enough pork loin for six, which is the number of people I was serving, sliced it into half inch or so boneless chops, and froze the rest of the whole loin. Then I sprinkled it with Goya adobo (which contains salt), cumin, oregano, ground chipotle, just a touch of ground cayenne, some thyme, and refrigerated these seasoned slices overnight wrapped up well. On the day of, I took a recycled produce bag, tossed the seasoned slices with plain flour to coat and fried in a little vegetable oil until golden. When done, and it doesn't take long, I removed from skillet, drained and blotted on cheap paper towels. Then I took the chops and quickly sliced into thin strips for use on the nachos.
I had already prepped all my other ingredients: Shredded iceberg and romaine, chopped Roma tomato, sliced black olives, Daisy sour cream, little slices of avocado, shredded cheddar, and crumbled queso fresco. I set these all out with a stainless bowl of heated tortilla chips and warmed plates and the sliced meat to let the guests assemble their own nachos, with the guests of honor first in line, of course. It was a huge hit, and I was very glad I remembered how much I used to eat when I was their age and as active as they are when estimating portions for the nephew and his girlfriend. 
With pork loin, it can be very good, but it needs some help. It hasn't much flavor on it's own, and it needs to be pretty quickly cooked so it doesn't dry out or get tough. There's not a whole lot of collagen or fat so trying to treat it like shoulder will result in epic fail.
ETA: I just remembered I also used some fragrant ground sage to season the loin chops overnight before frying.
