The ultimate example of a picky BP. Normally I would say this is a reason BP's aren't for beginners, but that would make me a hypocrite because Paarthurnax was my first and only snake. Think I got lucky with him not being too picky, but its definitely something you should watch out for! I've seen posts where a snake wouldn't eat because the color of the rodent offered was different than it was used to.
Yeah, I've heard they can be pretty picky. It is definitely worth it though!!