I've been using the worksharp with the Blade Grinder attachment for about 2 years now. For what it is, you are getting a lot of capability with just a few drawbacks.
1. It makes re-profiling very quick even on some tougher steels and then finish them on diamond stones or other mediums if you are worried about carbide tear out. Something to note though, when using the system on low angles you have to be very sure that you are applying virtually no pressure because the blade face can and will make contact with the belt and scuff up the finish. You can try and mitigate this a bit by taping your blade face with masking tape or electrical tape but if that course belt hits that its not going to matter much and will make quick work of whatever tape you have applied.
2. It also can help with blade maintenance if you set your angles right. I bought a leather belt from Super Strop (you can find them online) and loaded it up with some diamond micron past. Running fairly quickly you can clean up an edge after fairly hard use with just a few passes. It is also a great way to put a polish on some more stubborn steels rather than the hundreds or even thousands of passes you would need on a traditional strop and compound.
3. It is extremely difficult to sharpen the length of the edge. The system is great. But the biggest limitation that i have found is that it is almost impossible to hit the length of the sharpened edge. Towards the tip, even the steadiest of hands is going to struggle to apex the last few centimetres without going to far and rounding the tip off. Conversely, towards the heel of the blade it is impossible with many blades to get the last few centimetres there without running your handle scales up on the belt marring them. The best mitigation for that of course is to disassemble your folders and take the scales off but that defeats the feature of how fast this system is compared to others if it requires a full take down and reassembly each time it is used.
Bottom line; it can produce some great microconvexed edges in a fraction of the time freehand or fixed angle systems can. There are downsides like every system but they are not insurmountable if you are willing to put the time in.
