I would never keep a mbu, I do not have the room for a 500+g tank & all the filtration needed to keep the parameters where they should be. I do presently keep 8 tanks, many of which have fish over 20 years old & my fahaka puffer is ~12 years old now. I also run The Puffer Forum, so I have access to the top expert, long-term pufferkeepers in the world there.
Our Mentor, Robert T Ricketts, had his 26" mbu jump out. He & his wife were devastated. It was a long-term member of their family.