I'm sorry to hear that gentleman had poor luck with his Mbu. I raised mine to 24" or so in a 48" tank, then he later went into the stock tub for the six months during which our house was getting remodeled and he now happily is residing in the 300G. No stunting or other health issues. I've been keeping fish for 30+ years and never heard of half those "filters" described, above, and can tell you that all I have ever done is either a couple of canister filters + a sponge, the live plants (of course), or the new wet/dry's on the 300G.
Obviously, I have no firsthand knowledge of the gentleman you are quoting or of his actual setup in regards to the Mbu but I can tell you that you do not need all that stuff just to raise one (or pretty much any other freshwater fish, for that matter...), nor does it cost any more than any other fish tank in terms of power bill or upkeep. In fact, at first glance, I would say that he put the cart in front of the horse and needlessly complicated a simple equation and possibly, that has soured him on the whole deal. I know, for example, that if someone told me I would need an in-ground lift, a 3-bay garage, and $10K worth of tools just to do routine maintenance on my truck, I would probably never want to buy a truck again, either.
As I mentioned before, our Mbu has been unproblematic in terms of maintenance and honestly, I find him hardier and more robust than a lot of other fish we have kept. Are they for everyone? No. But that doesn't mean we shouldn't or couldn't try to keep them.
I would extend this invitation to anyone: If you or the gentleman who made the above post would like some tips or advice on keeping Mbu, feel free to post up in here or shoot me a PM. I am not any expert on this but can tell you that I have a very happy and healthy Mbu puffer who has none of the issues you apparently keep trying to "warn me about" or whatever, LOL, and am glad to share what has worked for me. Or, if you are ever in Central Texas, feel free to come by and see him and see the setup in person. My wife and I would offer you a beer or cup of coffee and you could feed him, yourself, and ask all the questions you want. Ditto to your friend who you are quoting. Thanks again for your concern.