I keep axolotls because the only word that I can ever think of to describe them to people who haven't seen one is "amazing".
They are strangely human-like in my opinion, and they make an excellent conversation piece.
I hate most dogs, goldfish, and most hamsters because they have been cross bred to be so different from their wild ancestors that it sickens me.
Axolotls on the other hand have been in captivity for over a century, and if you were to compare them to a wild caught individual, you'd still be able to see that they are clearly the same species.
Axolotls don't have strings of saliva that fling every where when they shake their heads. You don't have to clean up outdoor messes. You never even need to let them outside to do their business.
I have about 80 adult/sub adult axolotls in my basement, and I wouldn't trade most of them for the world.
As far as a needing a huge tank and a lot of clean up....
It might be useful to you to know that in labs they keep adult axolotls in 1 gallon squat fishbowls and change the water regularly. I keep mine in groups of 6-9 (depending on size) in 55 gallon tanks and 25% water changes every week, sometimes twice a week, and I do a 100% waterchange twice to three times a year. If that is your idea of a lot of cleanup, then maybe you shouldn't keep pets, because they aren't high maintenance.