I'm a VfR user from the first hour of the betas and use it as pro viz freelancer for living. For me there is no alternative for Vray, quality and speed are awesome, it can be universal used, it's open for complex scenes, large renderings, stable network rendering, it allow you to grow with your knowledge. But you ask for the VfR community?
The history is, that there was a very lively community at the beginning, but over a time of 5 years the plugin delevelopment of ASGvis was freezed, the community fall asleep.The pro user did there daily work, the plugin was rocksolid, no need to talk ... than ASGvis was adopt by Chaosgroup, the development started again.
The ASGvis team is using the same code for Rhino and SU, so, from time to time the focus of the development of VfR seems to be lost to the SU plugin. There is no big chance to talk about the development of features at the forum.
There is a beta user team that get access to the nightlies, over the months the plugin grows, but not so fast like expected. But at the moment the plugin starts to be more and more powerful. Since a few months I use the nightlies for my daily work, because the new features save me a lot of work and time. The plugin is stable. I hope there will be an update for every user soon.
VfR slow down the start of Rhino, I havn't seen other big slow downs. The image calculation is very fast.
The community needs users who like to be the community. In the past I was one of the core community user, but since I' am pro user, I like to use my spare time not for rendering most. The community needs to grow again.
For me the Chaosgroup forum is a standard forum, no problem to use it and I like the simple clean UI. It's open for paying customer only, but there is a public forum too. The VfR forum is not so often read by the moderators, I know the problem.