I have seen nutritional information before, lots of searching on google. The big thing to remember is that we don't know enough about BP nutritional needs to be able to definitively say that one is better than the other nutritionally given that they are so close. All that being said there is a compelling reason to feed rats. Rats are larger and you may want to feed your snake more than 30 to 50 grams (what XL adult frozen mice weigh) per feeding. Some snakes will readily take more than one food item per feeding but its much easier to give one appropriately sized rodent. If you feed live rats grow faster but can outgrow your BP. Mice take a long time to get much over 25 grams. I think at the end of the day what you feed your BP is up to you and your snake and what works for both of you. I break all the rules and feed gerbils. I have a great basement, where I can keep gerbils as pets as well as food. There are a lot of things to consider but I have never been convinced that nutritional value was much worth considering, at least for BPs.