When mining at home, noise is important too. But generally speaking, most of this technical limits (noise, remote control, cooling, etc.) can be managed efficiently. 

Which means that ROI remains the most important in my opinion.

ROI depends on the cost of the machine with import taxes, its reliability, the cost of electricity, the evolution of the network's computing power, crypto value evolution for paying bills and your ability to use the heat produced).

Consequently, to have a chance of having a positive ROI, it is preferable to have low-cost electricity that is stable over time to make the machines profitable before they are outdated. 

You also have to be lucky (or well informed) to know if a new generation of chips will not make them obsolete quikely.

And if you don't have a lot of machines you also have to be lucky for it to be reliable... (If you have a lot you know that you will lose ~10% of your hashrate during first mounths burn-in)