From a brief look, this is more or less a brain training wiki, but playing up the mentat training angle probably makes the site more engaging and fun.

I think there's a lot of people who wish they could remember more things, or math more effectively without tools or etc. Probably not a whole lot who want to go to the depths of the mentats. In universe, the training would have started before the trainee could consent, which makes it hard to make a choice to become a mentat, you can't choose to begin training, only to continue or abandon if you were in training since early childhood.