if you want to know quality of your , then you need to know what kind of materials which used to make that water filter system product. If you can, make sure you only make water filter system which made in the US. Just like another water filter system, you need to replace the filter inside in regular basis, that is why you need to get the one which is easy and affordable to replace so you can save more of your money in the long run.
A good filter should be able to last up to 12 months, not too short like 4 or 6 months, and just like i said before, the price of the filter should be reasonable enough. The size of your filter usually already a standard one, so you can use another brand too if you want, even i will not recommend it.