My brother-in-law did one he marinated in some sort of pineapple brine. The acids in pineapple could break down the meat too much but whatever it was he did really worked and it was a great loin.
A chipotle rubbed pork loin would be great as well.
What temp do you take your loins to? I always pull mine at 135-145 and they are always tender and moist.
Well I decided to use some KC Masterpiece Honey Teriyaki that I had on hand for yesterday's grilling. I added some Worchester sauce, Chinese 5 spice and lot's of chopped garlic. Marinated it for about 24 hours and it came out good.