The B&B model is on some, but the USA model is on others. Which is better is up for debate. I like the B&B myself.
The XL model is the model Nuno has/is using.
One source of confusion is that the 500XL was at one point called the 500L. So when someone says Nuno used the 500L, it's that, when Nuno started using them, it was called the500L, later someone requested a lower output version of the pickup, the 500L was renamed to 500XL, and 500L became the lower output model.