It is not necessarily an issue of tank quality.
If I get in my car today and feel colder than I did yesterday, it's not necessarily because there's a problem with the car. It could mean that I need to adjust the thermostat because it's colder outside the car today.
If my food is ruined, it may not be a problem with the oven. It could be that drying fruit needs to be done at a lower temperature than cooking a frozen pizza.
Vaping equipment, similarly, requires some adjustments from time to time.
The number of wicks I need in a Protank, for example, varies by juice. The number of watts I need varies by juice. If I get dry hits or a burned taste, it's probably because the juice isn't wicking to the coil fast enough to match the heat. I may remedy this by removing a flavor wick and/or turn the power down. If the atomizer floods or juice leaks on the battery, it may be something I can remedy by adding some wick back on or turning up the power. Over time, I think you'll find that small adjustments like these can fix a lot of the problems people sometimes attribute to "faulty equipment."