I've tried a bunch of the ceramic rods over the years.
I was very excited about the MAC black rod when it first came out. The construction was pretty different than a standard ceramic rod (it was a steel rod filled with silicon to absorb vibration from falls and then coated with fine ceramic). It was a really great rod. While it broke less often, it is not indestructible and I think that was a problem for MAC. It was also quite a fine rod, which is FANTASTIC for the many of us that hone often. It didn't work well for the many cooks that hone every few weeks. Because of this, MAC redeveloped their rod to use a coarser abrasive and to put abrasive grooves going down the sides. I find that the abrasive lines going down the side are horrible and often cause micro-fractures. I wish the original MAC rod that came out 3-4 years ago would come back since it was great!
The standard ceramic rod that is found most anywhere and has the black handle (comes in white 1200 grit) and grey (coarser) is a really good rod. It seems like it has just the right amount of abrasiveness and is remarkably inexpensive. There are better grades of ceramic used (Spyderco came out with a ceramic rod a number of years back that is beautiful quality ceramic) but it doesn't seem to really affect the quality of honing. I've found that creating a flat spot in the wood handle so that it doesn't roll does wonders for the longevity of the rod. A black paint pen makes it look like the rod was designed that way.
As a side note, it is really important to use ceramic cleaners to get metal dust out of ceramic rods if you don't want to see micro-chipping happening to the edge as metal dust builds up.
For what it is worth, when I was apprenticing under Bob Kramer, he was a huge advocate of ceramic rods and wouldn't ever use anything else between sharpenings.