Mine just died.
I had a Green Istlantum, he was probably 6 years old when he passed.
Between 11''-12'' with nice trailers and he was heavier than expected.
Great fish, not as owner interactive as an amph or parachromis in my experience but still a beaut and they are tough as nails.
Get him a female if you got the space, they'll get a nice hump for you.
Minimum of a 60 for an individual for its lifetime.
keep your water parameters very clean and maintain a healthy tank for them. They can be sensitive to slight changes in water as I found out the hard way.
All and all, I highly recommend it.