I have the KME and LOVE it.
I don't use the convex rod (and am not even sure what that is). I use the diamond hones: 50, 100, 140, 300, 600 and 1500. I have found that the 600 is often the ideal toothy edge for me, but I often find myself using the 1100 just because I like seeing the hairs pop off my arm. For maintenance, I use a Stropman strop with the black, white and green compounds. I have used the KME on all of my Fiddlebacks, and the results have been consistently awesome.
There are a lot of systems out there (Wicked Edge, Worksharp, Edgepro, Lansky, Sharpmaker, etc) and a ton of freehand options. While I enjoy playing with Japanese waterstones, I think that the KME is the best system for my needs. While the KME is only very, very slightly less capable than the Wicked Edge, it is significantly less expensive. To put it another way, I have been using my KME for around three years. I have never once regretted buying it or wished I had a Wicked Edge instead (or any other system).
The customer service from the owner of KME is spectacular. He will get on the phone with you, answer any question you might have and give you numerous pointers on how to use the KME. I once called him with every intention of spending more money. The owner talked me out of another purchase, helped me to improve my technique and sent me some free stuff. IMHO, KME is the Fiddleback of the sharpening market segment.
One more thing; the KME system does require some technique. Some folks think you buy a system with a jig and you don't have to think or develop skills. This is not true for any guided system. While systems like the KME take a lot of the guesswork out of the process, they still require you to understand sharpening basics. Also, there are techniques that are specific to the KME (or any system). Do a search of his site, read the threads about the KME and learn how to use it. If you do that, you will be amazed at the quality of the edges you will create.
Needless to say (but I am saying it anyway

), this is just my opinion. YMMV. Good luck with your purchase, and I hope you enjoy whatever system you decide to buy!