eMax crowns, should the face of the crown be smooth?

Dental crowns done with emax porcelain are generally more stronger and natural looking! It would have been great to see the picture of your porcelain crowns, so I can see if what you are talking about is the anatomical grooves or possibly other things. It is possible that the ceramic technician had incorporated grooves to make the teeth look anatomical correct, so you are feeling the lines, in this case your dentist can simply polish those off.

As far as the looks, they can be even also, depending on if you are happy? if you are not minor tooth adjustment and contouring is possible!

What you are most probably feeling and seeing is the texture that was incorporated in the porcelain of the crowns. Natural teeth typically have texture though it is very subtle. The texture of your crowns may be a little too much and that's why your noticing it. I would speak to your dentist about it. They can be smoothed down a little with special polishing wheels.