I haven't found a good breakdown on my questions so I thought I would post them here.

Since the content is mainly the same (from what I understand) in combined Rulebook, does that mean the reference cards from the sets are still a viable resource?

Along those same lines can I use the prior sets books a player guides now? Do they need significant errata to bring current?

I am thinking of purchasing the book so all the rules are in one handy location, just want to make sure how much of older sets are still useful.