Knifeedge just announced yesterday that they have repackaged the addons 1-2 and they are available to G4 users free. They are presently working on 3-5 and they will be released as well in the future and made available free as well
Also G4 version 4.00.051 was released as well, so you have to update your realflight prior to using the free downloads.
I have been waiting for the Viper 500...........looks like I will be waiting a little longer
Richard