There is a complete user manual online available to help you master the Windows PC Client. Check this article and let me know if you find anything missing.
A communication bug has been found in RF Explorer firmware v1.06. In certain USB configurations it may not be able to receive configuration changes from the PC when you use the Windows PC Client.
A fix and new upcoming firmware v1.07 is expected this week, together with a Windows PC Client upgrade.
As of early September, all the RF Explorer models and Expansion Modules are in stock at SeeedStudio.
We are currently working to have reference distributors in US and Europe. Stay tuned.