I spend most of my time reading technical manuals for microprocessors. I appreciate a concise source with as much information as possible as close as possible to the section I am studying. The companion bible offers word corrections in the side column, marking the alternate translations with a small circle above the word in question. This is barely noticable in the king james column and does not distract from reading the unaltered king james text.
I've noticed in reviews here that some of these corrections are controversial, but they can easily be verified by looking up the original language. I haven't found any inaccuracies, and have not found the occasional opinion included by Bullinger to be offensive, although I find him a bit too "religious" for my taste. That's understandable, because only someone very motivated would have worked so hard to produce such an extensive work.
All in all I'd rate this as a good bible for people who don't want to be influenced by other people's or churches opinions and feel capable to come to their own conclusion based on knowing all of the possible translations for specific words contained in a passage being studied. This bible might be confusing for a beginner, but for a beginner anything but a gifted teacher will be confusing, and it's better to stick with some technical help than to risk falling into the hands of a particular church's doctrine, which you will do with most modern translations.
When using this bible, don't be lazy, or else you probably won't get much value out of it. If you see a small mark over a word, go to the side column to see the alternate translations. Most of the time this will pay off well.