I only have Arabic references.
In short, they are like the Mo’atazilah in that they apply their logic over the verses and ahadeeth. They reject the coming of Isa, peace be upon him and also the torment in the grave. They have weird fatwas such as the permissibility in watching nude photos, shaking hands and even kissing a non Mahram woman. They say it is permissible for a non Muslim to lead a Muslim country and that the people living in the two poles don’t have to pray or fast!