Size. Lack of manuals in the box.
I think the smallest chemicals I've seen aimed at minilabs was at least 1litre. Most are bigger then that. So you're buying bigger bottles of stuff. That's not 1litre of diluted mix that's 1litre of concentrate.
The bottles I bought came with little more then the name on the bottle and a few lines. No big issue I went to the Fuji-Hunt website and downloaded the docs.
If you can figure out what you need I don't know of any problems with machine chemicals.