I've been through a few courses to date and have many more in a bulk purchase to go through, there is no time limit, there is clear and informative content (with the odd spelling mistake), but overall things are good, i would like to see a CDP point allocation for each course so that a total can be shown to employers or management, but otherwise certificates of competition are there, and who doesn't like a certificate to show their work. No real complaints, some content does need a little updating, but it wont stop a patron understanding the concepts or change how they understand things. Overall a good collection of courses, something for everyone. This is also not my first purchase, I've bought a few bundles with a possibility of going back again once I've completed my existing set.