Honestly, groomed or shaved is often better, in my opinion.  Especially if the gentleman has a lot of hair down there.  Pubic hair is generally coarse and hard on the tongue and face.  Also, it makes the area less sensitive to caresses or to a tongue. *wink*

That said, I also understand that sudden grooming in that area could be difficult to explain to one's significant other.  In that instance, I recommend using hair conditioner when taking a shower before an appointment.  It has the same effect on the pubic hair as it has on the hair on your head.