In my opinion, Burms seem to be like a big ball or boa when they are properly handled and tame. Retics do seem to have a different personality and intelligence but it always varies from snake to snake.

I had an albino burm years ago that was so laid back, I took him to childrens reptile speaks at a local preserve and nature center. He also went to one certain carnival with me every year which had a most exotic pet contest every year. He was wonderful. Then again, a friend had a green anaconda which was the very same way. He was invited to appear at our local movie theater on opening day of "Anaconda" to be allowed to properly educate people on the snake.

So it isn't just retics that can be like that. With the giants it really depends on how it is raised. Of course retics do seem to have a better memory and may never be the same if they experience a trauma in your care. They may or may not be the snake you can hand off to a friend. They tend to choose who to be comfortable with and who not to.

Just do research and try to get some hands-on experience handling big snakes of different species and ages.