I had one a couple of years back and I loved it. I bought it and it was a thin little pinner, buy the time the end came he was a fat little sausage. I think Kuli's are very attractive little oddballs. When mine was big he had a leathery smooth skin that was really pretty.
It is true that you will practically never see them, at least until they are ripened. It is in their nature to hide out, so play their game. I gave mine a clam shell that was plenty big for him. He stayed in their almost all day, and poaked his head out to eat. If you provide them with cove to make them comfortable and protected, yet angle in such a way as to reveal their hidding spot from the perfect angle, you'll have much more time to enjoy your kuli. That is what I did after about a year of not knowing he was even still around.
I could only imagine that he would have been more happy with some buddies for his clam shell.
My kuli at mostly detritus, scraps with the occasional shrimp pellet.
I like weather loaches too.