I own Realm Works and have worked with it for some time. I find it very useful for my own preparation and organization. Many of the player components are still unreleased, but it is a great organization and linking tool for GM use as it currently exists. At this point I believe that it is worth the price, but the final part of that decision still rests with how the player components work once they are released as I still that as a vital component of what I looking for. I have two campaigns that I have been working with in the program and find the automatic links and connections are a massive step forward from how I previously organized my campaigns.
It has a fairly steep learning curve and import of data takes a substantial amount of time, however i was spending a lot of time on my campaigns prior to starting with Realm Works. It is not a tool for a here and there sporadic GM. The creators are playing up the ability to purchase pre-made professional materials optimized and implemented in Ream Works, but they are still coming as the player components need to arrive first.
If you have specific questions, I will be happy to respond here or off-line.
Takeyabue