You need to decide WHY you are choosing a certain trap over another for skunk work. If you're simply catching skunks on a farm or other open area, trap style is not important. However, on 95% of my skunk calls, they are living under a porch or in an urban setting, and the number 1 concern of homeowners is spraying. It's basically the main reason they want them gone.... they do NOT want to experience the odor issue.
It is that reason I choose the PVC traps. Using an open-wire cage, you are is far more likely to end up with a skunk spraying all over the side of the home, or wherever the trap may be set. This is due to raccoons, foxes, dogs, cats or other animals (or people) messing with the trapped animal. The reason I use the PVC traps is to greatly minimize the chance of a captured skunk spraying.
Anyone who thinks the PVC traps are necessary to prevent YOU from being sprayed has obviously not handled many skunks. During fur season, I release all my skunks caught in DP traps on the coon line. I do this by hand, using NO type of cover over the skunk. I've done this for years, and have never been sprayed (yet). The point is: trap choice should be decided by what your goal is. Mine is solving the problem (removing the skunk) without the homeowner experiencing what they called me to prevent. Trap style (for me) makes no difference in regards to how I personally deal with the skunk.... it is chosen to provide the intended result for the client.