I own both knives. For the discounted price point where the Companion can be purchased, it is a good knife. The Busse line though, well, is different in every way that is important.
Busse handle is far easier to grip, to work with, and will prove more durable in the long run. The Busse blade, far superior in really every way.
The knives can probably best be compared this way: The Companion is a knife that is handy to own, and when it disappears you will think you owned one and wonder where you put it. The Steel Heart, the Mean Street, and the Battle Mistress are knives that effect an emotional attachment, really. This spring I was doing some tactical shooting in the wilds, and at one point we had to crawl through some really rough terrain. Late that night, I reached for my Mean Street...only to find it gone. Spent the next day retracing every step from the previous day, nothing. I was sick. Got home, my buddy was on the answering machine asking whether he could keep my knife! Turns out he had taken it from my drag bag, forgot to put it back. Boy, was I glad.
Buy a Busse, or 3. You will always be glad you did.