Just posted this in another thread, but full chisel only cuts better when it's freshly sharp. And unfortunately, it dulls quicker, and doesn't take much to compromise the cutting performance. If you are cutting dirty wood (on ground, or may have been rolled or dragged on the ground) you will be better off with semi-chisel, as it will hold up better and require less field sharpening. That improves productivity quite a bit. In my experience, it reduces the need to file by about 2/3.
The only time I use full-chisel is when doing mainly felling work where I know I will be cutting clean wood most of the time. Most of my pro saws come with a free loop of full chisel, and I run that until it's worn out. For replacement chains, I buy semi-chisel almost exclusively. It just has better real-world performance in my experience.
Full-chisel and semi-chisel sharpen the same with the same files.
As far as yellow versus green, the only time you will notice a difference is when plunge or bore cutting with the tip of the bar. If you aren't doing any of that -- i.e., mainly cutting along the flat of the bar -- you'll never really notice the difference between green and yellow, and can run green for a little extra kickback safety in cases where the tip might accidentally contact some wood. I occasionally have to bore out a tree, so I run yellow, but could get away with green about 90% of the time.
