I've been getting good results with the Work Sharp Guided Sharpener. In my opinion, it's more like a hybrid guided/freehand unit because the guides only set the angle at the beginning of the stroke and it's up to the user to maintain that angle throughout the stroke. The guides can be removed for freehand sharpening which is the way I've been using it lately but the guides were helpful at first to get the muscle memory necessary to maintain the desired angle.
The reason that I like this product so much is that it solves one of the biggest issues I always used to have with sharpening. Maintaining the correct angle at the blade tip.
The Work Sharp has a feature that they call the Pivot Response System. As the edge of the blade begins to curve toward the tip, the stone holder pivots to compensate for the change in angle. I was a bit skeptical about it until I used it and discovered that it actually works and isn't just a gimmick. A very simple yet effective solution to a problem that many people have with sharpening.
Here's a link to the product and a pic of my own.http://www.worksharptools.com/sharpener ... ystem.html