石英石： pro: maintenance free, you never need to seal it. No radiation.
con: not as beautiful as the natural granite.
花岗石：
pro: It has the natural beauty.
Con: It's natural, so it has some pores. You need to clean it (maybe within 12 hours?) if you spill milk or soy sauce or other stains on it. Otherwise, it might leave stains on the countertop. Granite emits radon gas. The level is very low and poses no health concern for most granites. But a very small fraction does emit radon gas above normal level.
