Quartz is more resistant to many of the abuses of a kitchen, but either stone will chip or scratch if, say, you cut on it without a cutting board. Otherwise, it's more about look -- natural granite has lots of interesting and varied patterns, only some of which can be imitated in quartz.

For me, I wanted a quieter countertop, so performance was the determining factor, but there's no simple right answer.

Chips in the sink edge is fabricator error and will happen with any material. A fabricator should have enough sales skills to sell the value a larger sink edge profile, especially considering how much I charge to fix it after its installed.

Pitting in quartz is customer abuse usually, but quite natural for some stones.

There are tradeoffs to be made for every material. You've got to continue your research. I'd search out a shop that sells all materials over one that sells stone alone.

As a fabricator, I have noticed an increase in the Quartz demand because of its minimal maintenance. But ultimately, it depends on the look you are going for. Granite has its natural patterns and movements that you will not find in Quartz, but you do have to maintain it with sealers and cleaners. If there is damage on a granite countertop, it is easier to fix or patch up, then a quartz countertop.

But like I said before, it all depends on the look that you are trying to achieve.

If the possibility of chipping is your big concern go for granite, the pattern will conceal small irregularities.

Your countertop will probably need seams in some places. Make sure whatever you go with that you discuss how the seams will look. Many granites and some quartz have large patterns - it is like sewing with large pattern fabric, a seam can be made more or less noticeable depending on where the cuts are made. One of the things I like about my quartz is the seam is barely noticeable.