Sound quality differences in streamers

Assuming all things being equal, yes, significant differences. Most good quality streamers do not have a DAC. They are simply stand alone. If you have a good DAC you don't want to buy one with the DAC function. You want all the effort and cost to have gone into only the streamer function. 

Also, lots of memory to store ripped files is becoming less prevalent as streaming can sound just as good as stored files or CDs, so there is no use for storage. 

But it depends on the rest of your equipment. My rule of thumb is that if you purchase best in class and synergistic components then investment levels typically look something like this. 20% speakers, 15% amp, 15% preamp, 15% DAC, and 15% streamer. Or better 25% speakers with the rest split equally among the components. 

The point of the above is that each component is equally contributing. 

This is because careful and thoughtful design and top notch subcomponents get you insulation from electrical noise, and vibration, and stable power...etc. from the start to the finish. 

I have owned DACs and Streamer from a few dollars to over $20K. The differences are obvious at every level. 

In my experience, which is primarily related to using Roon, the answer to your question requires separating the server from the streamer since they perform two separate functions.  In the case of using Roon, the server runs Roon server, or Roon Core, which manages music files, streaming services, and the audio devices on your network.  The streamer operates as a Roon endpoint, which clocks, processes, and transports the digital signal to a DAC where it is converted into an analog signal.  In some cases, the server and streamer exist in a single chassis, like with the Antipodes K50, the Grimm MU1, and others.

I have not heard noticeable sonic differences in the servers that I have owned.  However, I have heard meaningful sonic differences in streamers, with the best sounding streamer I have owned being the Sonore Signature Rendu SE Deluxe, which is currently in my main system.  If I didn't already have the Sonore streamer, the other one I would try is the Innuos Pulsar.

Streamers vary greatly in the amount of noise generated from within, noise is the enemy of resolution/transparency. In researching and comparing streamers you'll find much difference in the lengths some makers go to lesson noise. Every single component on motherboard can contribute to a lower noise floor. Proprietary operating systems and linear power supplies also contribute greatly to lower noise floors. Streamers set the resolution/transparency floor for the entire streaming chain, extremely important component, perhaps the most important component in the entire chain.

I heard a significant increase in clarity when I switched from a Roon Nucleus to a Grimm MU-1.  I thought the upgrade was well worth it.  So yes, there is a difference.

First of all, it’s dCS, not dSC, and to my knowledge, their least expensive model starts at around $22,000.

Personally, I don’t own (but have auditioned) any streamer over $1,000. That said, I believe you can clearly hear the difference between a Wiim and a truly high-end streamer—at least in terms of pricing. This belief comes from the ability to easily distinguish differences among sub-$1,000 streamer/DAC units out of my humble system. The real question is: where does the point of diminishing returns begin?

Price doesn’t play the music. For example, my $399 Cambridge Audio MXN100 sounds noticeably better than (1) the $330 Wiim Ultra (with Smsl ddc), (2) the $399 iFi ZS, and even significantly better than the $850 Eversolo A6. All were tested using their internal streaming sections, the same external DAC, and low-noise power supplies. The sonic differences are apparent and, in my opinion, may mostly come down to two specs, including (1) jitter noise and (2) electrical noise, that one needs to watch over in selecting the gear.

Finally, I encourage you to treat your room acoustics, optimize speaker placement, carefully select cables based on specifications (not ad-hoc recommendations), be mindful of system synergy, and train your ears to better reveal those differences.