I chose to try beard dye for the brows since I've often heard good things about it, I probably will never go back to "regular" brow dye. (Note: before is on the right and after is on the left in the attached picture.)
+ Extremely well-covering and stays well. With e.g. Depends dye, it has never taken the small hair strands, so I've always needed to dye extra in rounds to get a good result.
+ The packaging contains tubes with dye and developer, so you only need to mix the amount you need. You also get tools for mixing included.
+ Easy to use and apply. The dye has a good color from the start, so it's easy to see what you've covered. The dye is so pigmented and somewhat penetrating that you don't need to check that all hair strands are really covered.
The only negative, which isn't really negative, is that it set a bit too hard on the skin as well. My brows looked much darker initially because of that. However, it was easily fixed, luckily, with Vaseline. If you get too much dye on the skin, you can cover the brows in Vaseline and then wipe it off after a while (I had it on for 15 minutes x 2). Don't let it dry out, so feel free to put plastic wrap on the brows while you have it on (or do like I did and slather on a thicker layer).