I had one fitted recently and i like it, i have never had an RNS so i couldn't compare ( as i only recently got my first Golf). I can play other media- movies etc from my ipod as standard, streaming audio not an issue for me nor is the ipod cable in the glovebox as it isn't a big stretch if you need to use it. When i looked at the RNS when you start adding BT,MDI etc it was a comparable cost. I paid £800 for my unit from a dealer (within last month) cam with VW splash and warranty and i got a fellow to fit it for me (from another forum) at a very good rate- mic/and BT as well properly placed behind panels - a great improvement on my rcd300 but as i previuosly said couldn't comment on better or worse than RNS- i would imagine at the end of the day it is just different.
OP if you want the details on where i bought it from let me know