Sink Undermount Options
There are pros & cons for each type of reveal:
Positive Reveal. The sink shows; granite cutout is slightly larger than sink
Pros: Easier to clean b/c you can see the gunk and can easily wipe it off (it only gets nasty if you leave it there)
Cons: Silicone (caulk?) is visible, but if they use clear you won't see it when it dries
Negative Reveal. The granite overhangs the sink; granite cutout is slightly smaller than the sink
Pros: You cannot see the gunk buildup or silicone
Cons:
You cannot see the gunk to clean it.
Dirty water/food can splash up & under where you cannot see to clean it. It's difficult to see underneath w/o leaning way over & into the sink.
Dishes/glasses have been known to break b/c when you lift them out near the edge of the sink the dish hits the stone counter & can break (or, if the dish wins, the counter could chip...but I'm not sure how likely that is).
Zero Reveal or Flush. Sink & granite are flush or even; the granite cutout & sink are the same size
Pros:
Easier to clean b/c you can see the gunk
No platform over or under for the gunk to collect
Cons:
More difficult to do perfectly
Silicone is visible, but if they use clear you won't see it when it dries
You will find proponents of all three types of reveals here...but in the end it's what works best for you.
Q