They all have their good and bad points, you'll find knives and angles etc. that none of them are perfect for. You'll find people out there that swear by and at every one of them. In the end I think the individual needs to find what works best for their needs by trial and error.
One thing that can help is to look at what you own for knives and what you cut everyday and how much time you want to spend sharpening. For example I see a lot of people talking about 5000, 10000, etc. stones but in my experience for general everyday cutting such a finely polished edge is impractical for most tasks I do. I much prefer a medium grit stone say 600 to leave a more "toothy" edge and then maintain it with medium ceramic stones on the sharpmaker. For me the same is true for stropping, I can strop and edge and get it to glide through phone book paper, but during a day of cutting various other things it gives up long before the toothy edge will on the same blade. Perhaps using a black coarse compound would allow stropping to maintain but still keep some tooth in the edge. Now for a deboning knife that super polished edge glides through meat.
For years I used the lansky and sharpmaker combo and honestly it never really failed me. I recently decided to step into the spendy sharpener market and picked up a Edge pro, and a work sharp, and I had some time on a borrowed wicked edge.
The work sharp KO is great for re-profiling, or kitchen knives, it's fast, but for me my technique isn't consistent enough that after sharping several sets of kitchen knives that I'd feel comfortable doing an expensive knife start to finish. For some reason my angles are always skewed a bit. For example I can set the guide to 18 degrees and when I'm done I go to touch it up on the sharpmaker and the right side is always steeper than 20 degrees on folding sized knives (I end up with like 16/22 even if I try to adjust my technique), no problems with kitchen knives. The guide is not ideal on thicker blades. I've used an angle cube on the sharpmaker stones and they are right on at 20.X each side. This isn't a deal killer except again the sharpmaker is the perfect fast edge maintainer for me, so a system that I can't get consistent angles on to work with the sharpmaker isn't ideal. I had no issues rounding tips in fact I thought it was very easy to keep a nice point, and I like that you can keep the angle the same for the whole blade easily by rotating the knife as you draw it through and the idea of convex edges. I'm keeping it for kitchen knives and those knives you want sharp but don't "love". Also while it's very fast, almost scary fast, a lot can go wrong in a hurry. I've also used it for putting a quick regrind bevel on knives that were very steep before moving to the edge pro so it goes faster.
The edge pro gives amazing results, but it's slow, it's messy, and it's high maintenance (having to flatten stones, etc.) It's also very knife specific, it works great for knives with big flats on them, but many folding knives don't have that these days, and even with putting powerful magnets in the base some knives just don't sit on it solidly. Having to hold the knife on the platform solid and using the other hand on the stone to me just introduces too much variation (admittedly a personal issue, plenty of guys do it without problems). I have a couple of folders where the thumb stud does not allow the stone to hit the entire blade length. I don't use it as it's intended in that I don't move the knife blade on the base, I tried that and it's too inconsistent except with big kitchen knives. Especially as you move to the tip there isn't enough knife blade to ensure it stays flat, so now you're moving the blade in and out with variation and it's not sitting flat on the base letting it move up and down. To me it would be better served with a clamp to hold the knife still, though magnets help a lot. It's far too much of a "process" to use for a quick touch up unless all your knives were at the same angle so you could keep the thing setup.
Lansky, it's portable, gives pretty good results, and is pretty cheap even with diamond stones. The new versions seem to be lacking though, the new blade clamp is pretty poor compared to the old one, and even the case is made of cheaper more brittle plastic. Lots of knives don't have good places to solidly clamp to and the new clamp is even more picky about it than the older version. You get a lack of edge angle options.
Sharpmaker, to me it's more of a maintenance tool, I'd hate to have to reprofile an edge with one. It's perfect for a weekly touch up, but there's not much for angle options, and over time it's very easy to round tips off. The more narrow stones (lanksy, sharpmaker etc.) easily slide past the tip and round them over time. I rarely use the fine stones, much less the ultra fine that seem so popular these days. The medium ones give an edge with bite that still easily shaves and slices paper. Many folding knives I get come with a factory edge over 40 degrees inclusive so it's not ideal for that, you can angle the blade but it's hard to do consistently and that's key for a sharp edge. I would not want it for my only sharpener.
Wicked edge, I hate to say it but it's a lansky on steroids, which isn't a bad thing the lansky is a good sharpener. Now it does give much better results, on par with the edge pro, but it has the same problem of having to re-clamp the blade, or deal with changing angles, which is significant on blades with a lot of belly, and few folding blades are solidly clamped toward the tip with bevels, tapers, false edges etc. I like the diamond stones, that need no maintenance. For me I didn't like the blade position, I'd rather have it tilted toward the user at about a 30-45 degree angle, on knives with belly it was too hard to ensure I was getting the tip without sliding off it rounding it, that could be accomplished with an angled base to mount it on easy enough. Plus I'll just say it, price, if you want the fancy parts it's $700. You could buy all the options for all the other sharpeners I've talked about and not spend that much.
The weakness to all these systems is that so far no one has come up with a way to secure a variety blades solidly but also allow the movement needed to keep the stone perpendicular to the edge on blades with belly. I've always thought guides like the one on the worksharp need to be larger, with more flat area to align the knife with to increase consistency.
I guess the moral of the story is they all work and they all have problems. In the end having spent a silly amount of money on sharpeners over the years I honestly don't think I've gained much in real functionality of my edges over my original setup of the lansky/sharpmaker combo. Mostly what I gained was versatility and a bit of consistency, but with a very high price tag.