Ok Mr. Skarb I will chime in.
I have owned all the above systems at one point or another. Gatco, Lansky, Razor Edge, Spyderco, Skarb, and Edge Pro. Of these I sold off the Gatco and Lansky. They are OK but the Skarb and Edge Pro are in a higher class. If I had to pick between Skarb and Edge Pro it would be a hard choice.
I use both to initially set the bevels or thin out the edge. Do to ease of operation, I use Spyderco for edge maintenance. The spyderco system is the most versatile but it sucks for fast removal. Both Skarb and Edge Pro will quickly thin out blades. Both require some skill. Both can adjust to any common angle say from 15 to 30. Neither will do serations. Edge Pro requires a little more set up time. It works with the stone above the knife which is something I don't like as well. For some blades particularly folders its harder to hold them on the platen while sharpening due the geometry and lack of wide enough flat area along the blade. You have to change hands to do the opposite side of the blade and that is s awkward too. All that said, with practise you can overcome these problems.
Now for the Skarb. It uses a clamp and that can be an advantage. It cuts along the edge of the blade, more parallel to the edge. Imagine you had a very long knife and you held the stone and ran it along the edge to sharpen with the blade with the blade stationary. That will give you an idea of how the Skarb cuts, even though the stone is sationary and the blade is moved. Since it is used along the edge more of the blade at the front and middle spend more time on the stone than at the inside edge. This not really a problem because you just spend a little more tine and short strokes in this area. I like that I can use any stone with the Skarb, even the triangular Spderco stones. Maybe you can do serations, not sure cause I don't own any knives with serations.
Both Skarb and Edge Pro work well. All of these systems have been reviewed many times in the knfe review forum.
------------------
Roger Blake