For those who might think that such private RPC node doesn't serve the network. Of course it does serve the network. It will reduce load on other public nodes leaving those resources to those who can't run their private nodes.
I've finally setup my own full-RPC steemd node on a 6 core Xeon server with 256GB of ECC DDR4 RAM, in a datacenter nearby SteemData (over private, 1gbit network with sub 1ms network latency).
SteemData is open and free to use, but unfortunately its not a HA setup (high-availability).
I do have ~200 active connections on MongoDB alone, from various users and apps.

The database has been rock solid so far, and there is a fairly easy scalability path:

add more RAM to database server for high-performance
create a replica cluster for HA & backup purposes
The weak points in SteemData right now are:

node stability/availability
bugs in my codeBut still impressive results as the systems has been stable and supporting so much application. I particularly like Steemdata as it helps me navigate my own feed just in case I miss anything and helps me monitor users active users...probably we can get more dedicated team on the nodes as it goes down something but this one has been lengthy, I am not to sure of the overall effect it has on the platform...apart from that fantastic work...