It's not "another" mfw modder.. there are *no* mfw builder released so far.. only .pup and .bsdiff files, which are all closed sourced. If waninkoko or kmeaw decides to stop working on it, then everything is lost and everyone needs to restart from scratch. This gives a unique framework for people to actually customize their MFW their own way. And to keep all the knowledge open sourced. Maybe you like waninkoko's firmware, but others may disagree.
The app has about 65 options for the users, the backend is robust, we tested almost every combination, on 3.15, 3.41 and 3.55, and tested it on over 15 different PS3 models, we had no bricks at all.