I have been using a size large avanti Quattro for a couple of years. I recently upgraded to a pair of hard soled fourth element boots size 11. I can tell that the boot doesn't go all the way into the size regular foot pocket. I picked up a pair of XL on closeout that came with the old style ABS straps. I would like to upgrade to the bungee strap. I am not sure what size to get with the XL fin and size 11 boots. L or XL ?