The 38 lb girl that was sold was actually listed on Fauna. For us she was puppy dog tame, never struck at anyone, and we completely trusted her. The new owner is having issues with her striking and getting used to her new environment. I've heard, but not seen it documented, that blood pythons are in the list of the 3 most intelligent pythons and can become one owner kind of snakes, so maybe she was used to my family or maybe it was just the enclosure changes and smell changes that set her off I don't know. We have hopes that given time to acclimate she will calm down and be the passive easy to handle snake my wife and I have known for 4 years. Once she settles in she will be able to be viewed at the Texas Serpentarium and Reptile Museum and possibly even handled.
We keep a fairly small and limited Red Blood python breeding collection. From our experiences we have had calmer animals that are much easier to handle by keeping them in a rack system (ARS-8514 and ARS-9006). I think it has something to do with approaching them from the top compared with head on as you would in a display type cage. I would also like to point out that we don't use hooks with anything and with our red blood pythons we only feed frozen thawed.
We tried keeping a pair of borneo pythons at one point, but both had bad attitudes and we sold them. We had one male red blood python come through that was devil spawn also and he got moved to someone interested in the challenge. All three of these though were kept in front open display type enclosures, and I would be currious at how they would do in a rack considering since we went to the rack we have had only one that has a mild temperment issue, but it only comes out when your holding him for more than a couple minutes.
As far as predictable goes, I think if you work with them enough you start to see that look that comes with I'm not in the mood right now compared with I'm cool and you can touch me.