Is the Roon Nuceus device a good streamer?

The Aries isn't an alternative to a Nucleus. It is roon ready but you still need something else  to run the core. 

I have owned a Roon Nucleus Plus server and give it two thumbs up.  It's really well designed and made and the USB port is "dead quiet", really good sounding box.  It also has the Roon software installed and "automagically" updates itself.  I've never experienced a problem with my Roon server, I suspect you won't either.

Ejr1953
do you also have a streamer?

Roon nucleus includes streamer in its description, but hearing need for a separate streamer.  Very confusing.

You don't "need" a seperate streamer for a Nucleus you can connect it directly to a DAC by USB but you can use a separate streamer if you want.