What Are Two Main Differences Between Crowns and Porcelain Veneers?

“What a couple of reasons one should opt for a crown over veneers?”

The most important difference and benefit to you as a patient is less precious tooth removal, therefore less sensitivity, less problems on the long run.
Dental crowns require a 360 degree tooth reduction and removal, once the dentist cuts, you can not add on the the precious tooth structure.
Unfortunately I have seen thousands of patients thinking they have porcelain veneers, or their dentist told them they are getting veneers, where in fact most of the tooth is shaved down, and it is almost like a 3/4 crown , or 7/8 crowns.”

There is no going back from a dental crown to porcelain dental crown, if any problem arises the next stage is root canal, or possibly extraction and last dental implant. 
However, if a problem arises on dental veneer, that can not be repaired or make anther veneer, worst case scenario, a crown can be fabricated.
The next big advantage is the cosmetic effects, in which in my opinion veneers will look much more natural than crowns.

Los Angeles Cosmetic Dentist