If you want them as a real boyfriend jeans take your normal size. That's why I would say they run true to size because they are made for wearing like a boyfriend jeans! If you want to wear them tighter you can size down 1 size but in my opinion they loose their "easygoing" style and appear like a normally crop jeans in that case ...
I must say that out of all premium jeans out there, AG makes the prettiest washes. These ex-boyfriend crop in 17 years are absolutely beautiful. Much prettier than current/elliott washes (I own 6 pairs of current elliott in different washes). They fit great too. They are definitely more rigid than current elliott. Although I think current elliott jeans are more comfortable since the fabric is softer compared to AG. These jeans run about half size to 1 size big. I wear 28 or 29 depending on the brand and the stretch and I wear 28 in these ex-boyfriend ones. These are must have for the season. You won't regret it.