This ball is a must have, especially for Magdust users. I've been using Magdust for almost a year, which is the best chalk I've ever used and is notably much better than all 4 other brands I've tried. My only ever point of dissatisfaction was the higher end price. Luckily, the Magball is here to save the day!
The ball is porous enough to quickly deliver chalk, but not having it spill everywhere and making too much dust. It is easy to open and close, and does not accidently open with use. The ball works great with Magdust, and has provided a way for me to use chalk more efficiently. I use the ball all the time for bouldering, only requiring loose chalk for those more technical crimps or for filling my pouch for a roped climb.
The Magball is truly a lifehack. It is extremely affordable, and will last almost as long as a pack of Magdust. Most importantly, this will save myself, and you, a lot of chalk (and money) in the longrun. The Magball lets you do more with less. No reason not to have this in your inventory of gear if you enjoy good chalk.