The above statements are, in my opinion, all true. The reason a mandarin is considered difficult is the food requirement.
I have a 110X with 40 gallon sump, tons of LR, fuge, etc. I specifically designed my rockwork in the DT to create pod havens where they can multiply but the fish can't get to them. It took me about a year to get comfortable enough with the pod population I saw in those areas to add a mandarin. And now she is very happy and gets along great with everybody. I have every confidence she will do just fine in that tank.
That being said, she lived for that prior year alone in a 30-gallon with some LR and a canister filter filled with LR, seeded about every month or so with a canister of pods from my LFS. She gained weight, grew, and did just fine. So her food cost me $20 a month.
Of course, ORA claims that their tank-raised mandarins are all eating prepared foods when shipped from their facility. So, if you buy an ORA tank-raised mandarin, all of the above might not be a concern. But, if you happen to get one that decides not to eat prepared foods after all, then all of the above will apply.
FWIW, I hear the green mandarins are easier to get to eat prepared foods than the blue mandarins.