Having always used myth, I tried VDR out the other day (am in the UK). I managed to get it working on my core relativiely easy (using the wiki) using the Kworld 399Us (again, using the wiki). And I liked it!
However, I didn't realise that further setting up was required for each of the media directors (I always thought that once stuff was working on the core, it would then work on all the MDs!), and this is where progress stopped for me as I have not been able to find any instructions to get this working. Just thought I'd mention it.
If anybody does know of where I might find these instructions, please let me know! Cheers.