Are all streamers the same?

@jji666 makes a good point about there being a difference between a server and a streamer.  In the Roon world, the server operates Roon Core and selects and/or stores music files while the streamer (or Roon endpoint) interfaces with a DAC.  All servers are basically computers.

In my experience, having a server connected to my home network, at a location away from my audio systems, and connected to my streamer using an optical cable, has resulted in zero sonic difference being noticed between the three servers I have had in my system over the past year.  

OTOH, switching from a Metrum Acoustics Ambre streamer (a Raspberry Pi device with LPS and femto clocks) to a Sonore Signature Rendu SE Optical resulted in a noticeable improvement in the sound of my system.  With the Sonore streamer, I perceive a richer tonality and greater dimensionality, which results in a more natural and musical presentation. 

Getting to an adjacent topic, but yes, there is little logic in thinking that, as long as the server device has sufficient processing power, that the packet stream across the network to the rendering device could be any different.  That's the beauty of Roon's configuration. 

I would also agree that DACs can sound different and that different inputs on a DAC may sound different (optical vs coax vs USB etc.) albeit I think a bigger influence is the analog implementation of a DAC.  Thus, playing around with different configurations may result in something more pleasing. 

Not wanting to whip a dead horse, but I didn’t see anyone mention the fact that some streamers have better clock chips than others, so a bit less jitter is always a good thing, even if it borders on the inaudible.

The other issue is to make sure if you are feeding a DAC from a streamer, and if the clock chip in your DAC is better, that it is doing the driving and not the clock in the streamer. i.e. Use whichever provides the less jitter. Sometimes in order to get that to work you have to use USB or another input. Or even a DDC. As @jji666  states, experiment to see what sounds best to you. 

We can hope that more expensive streamers use better clock chips and provide "cleaner" output, but YMMV.

Regarding WiiM, they have been very good about upgrading software based on user feedback, far more than some "high end" streamer companies. They know the Ultra had some issues at rollout and are working on them. At least they aren’t Sonos. LOL.

I’ve compared their O/S with that of a friend’s Bluesound Node 2, and I find WiiM’s just as good if not better. [I don’t use Roon].

Software bugs are one reason I generally wait about 6 months before jumping on any new device. Manufacturing quality also generally gets better over time as changes are made in the assembly line process. I plan on buying one around Christmas to feed an external DAC via USB, hoping by then most software bugs will be worked out.

I have three of their cheaper products feeding "cheap but better" external DACs (Schiit Modi) in a few systems (garage, outbuilding, and bedroom) and for the most part I have had no problems using them over the last couple years. I’m using Android and Windows PCs. I have no idea how well they play with iOS or Macs.

I have built several PC servers - the most recent being a 2box one with a paul hynes PSU. It sounds considerably better than the earlier builds easily challenging my vinyl for sound quality. Recently obtained a Grimm MU1 which is better again, the; flow, separation, energy and clarity improved. The USP being AES rather than usb to DAC conection and very sophisticated clocking of the output signal.

It sounds even better when used as an end point from my PC server.

I like the analogy to cars. A whole lot of marketing but essentially all the same.  Numerous superficial differences yet what matters most is where you drive in the car, whether it gets good fuel, and of course reliability. To quote Paul Simon, “cars are cars all over the world.”