StreamNet vs. UPnPTM server and a couple Naimnet questions

I know I have asked this before, but cannot find the answer.  First, is there a sound difference between StreamNet and UPnPTM?  Second, what are all the devices that work on StreamNet. NS01-03, both HDX's, both Uniti serves, Naimnet amps,   

I have a NS01, which I like.  Though it kills me that this hard drive keeps spinning away for days on end, knowing that I never use it and the on board storage.  I know that OS resides on the disk in the Ns01.  So I have been heavily contemplating an Uniti-SSD, but wonder what options I have for playback in other rooms, that are StreamNet enabled?  If StreamNet is thought to be audibly superior, I will stick with it, just wish there were more player only {no hard drive} options.

My other questions are, can you run StreamNet and UPnPTM simultaneously from the same NAS?  Any issues. 

Finally, do Naimnet amps support internet radio.

Thank you