Swivel knife 101. The knife really doesn't matter as long as it swivels smoothly in 360 degrees. Aside from that you could use a stick or a screwdriver. What really matters is the polish on the blade. If its not mirror smooth, you will get that described chatter. Very few blades come from the factory in usable condition and you may have to finish the edge yourself.
its easy to do. Get yourself some 400 and 600 grit wet dry sand paper and a strop with some red, green or black rouge. I prefer green myself. Find the angle of the blade and gently polish the blade with even strokes on each side, until you see even sanding marks. Then switch to the 600 and repeat. Go to 800 if you want, then do the same thing with the strop. Once your bald has a mirror smooth polish, it will carve like butter.
How long it stays like this is dependent on the quality of the steel. There are good and bad steel but they will all work. You may just have to strop more than others. Right now, the best blade steel is from Leather Wranglers. It requires less stropping than any other blade out there that I know of. The worst are the blades from China. Tandy has a variety of good and bad blades, each in varying degrees of readiness. The end result is mirror polish. At that point, the blade doesn't really matter as far as smoothness. However, you mentioned varying angles. I stay away from anything thats very steep. Straight or low angles are easier to control and give better results. They also jive the user more confidence as you aren't fighting the geometry of the blade while cutting.
Now, ceramic blades are a hot button topic. They work if polished properly, but they're brittle if you drop your knife (It happens), and I have yet to see one with an angle that's worth a shit. I have spent a LOT of money on swivel knives and blades and I use most of them a little, but one is my go to blade. I prefer steel as they are easier to maintain and replace, and they are generally less expensive.
If you subscribe to the Leather Crafters and Saddlers Journal, I did an article on how to take a shit blade and make it useable. Basically what's above with pictures. Also, I have a website with videos that cover everything you could want to know about setting up your knife and blades. check it out. www.learnleather.com or find the banner at the top of the home page!