Fixing problems on your edge is a pretty quick thing with diamond hones, but I haven't yet found a diamond hone which can polish the bevel as well as a ceramic. I know that they're available, but for a bench stone they are extraordinarily expensive in that fine a grit.
Think of sharpeners more in terms of grittiness then the material they're made from. Diamond works great for removing a relatively large amount of material, and when it clogs it's easy to clean. That, and its durability are its strengths. This makes it ideal to carry in the field.
Ceramic clogs faster and is harder to clean, so removing lots of material is not its strength, nor is durability. But it is aggressive enough and is available in very fine, uniform grit. Generally less expensive than diamond, all things being equal.
In conjunction, these 'new' sharpening media can perform almost as good a job as quality whetstones, more easily, more compact and with less mess.
However, nothing can rival good stones and a practised hand. Good sharpening is all about experience and patience really, and has less to do with technology than most people think. That, and knowing the properties of the steel alloy you're sharpening will always ensure your knives are not just sharp enough, but sharp.
What I use are DMT diafold sharpeners, (medium/fine, extra fine), Spyderco ceramic rods, medium and fine, and a Spyderco extra fine bench stone. Working from the coarsest diamond hone down to fine ceramic, then extra fine ceramic provides me with a long lasting, highly polished edge which is very keen.
Rosarms bevels are extremely easy to polish, but it is difficult to remove the wire-edge due I think to the titanium content of the steel alloy. I usually do the regular sharpening procedure from coarse to fine, but then go back with either a medium grit ceramic or fine grit diamond to remove the wire-edge, then finish the edge with the extra fine ceramic bench stone. A good edge on a Rosarms knife will not degrade very easily, and I have found the steel alloy used to be one of the best I've used ever.