Stone walls give homes and other kinds of buildings a particular character. They may look like classic or rustic buildings. If this fits in with the blend of an area, it’s a good look. However, if every other building is made out of bricks or wood, it might look out of place.
You also have to consider the durability and strength of the original structure. Even though synthetic stones are lighter, there will also be some weight added to the building by the new facing. This is not usually a problem, but if you aren’t sure, you should ask experienced contractors or engineers what they suggest.