Tab knobs feel good when turning.
The installation manual does not contain installation instruction for this specific tab and the other installation instructions in the manual for other products are vague. So I guess it I have to figure it out myself (can't be too difficult).
The only substandard part is one metal hose of which I am not sure what to use it for (not described in the manual) and it is made of thin material. I would replace is by a high quality flexible hose. For the rest it all seems to be high quality material.
In conclusion for this type of faucet prices are usually double at least. Good deal!