I also have the Wicked Edge. We had a good discussion on it (
http://www.thehighroad.org/showthread.php?t=642255&highlight=Wicked+Edge) here if you haven't read that yet.
I also went with the Pro Pack; but have not yet gone with the 1200/1600 ceramics and the balsa strops. I keep cutting up the leather strops accidentally (razor sharp edges will do that) so I am interested in getting the balsa strops. The 1200/1600 also provides a nice in-between step from the 800/1000 in the Pro-Pack to the strops; but you can get a mirror edge that will cause hair to jump off your arm just using the Pro-Pack and nothing else. However, if you have some of the really hard super-steels, you might be interested in the super-coarse stones to go with them.
Overall, I have only had a few real challenges so far - one was sharpening a 10" knife. While I could have done it with one setting, you get the slight change in angle at the ends of the stroke, so I ended up sharpening the blade in sections to keep the angle constant. However, to the best of my knowledge that problem exists with pretty much any angle/clamp system.
Another challenge was a bayonet I tried to sharpen. It was a pain (literally and figuratively) since it didn't have a flat side to set against the depth gauge and having edges on both sides soon taught me to pay closer attention to what I was doing.
Getting knives set up on the Wicked Edge can take a little bit since factory edges are frequently a bit imprecise. Once you get both bevels set up to a true 15, 17, 20, 25 degree bevel, etc. though, they are really easy to maintain.