First I would like to start by saying that I have A/B tested 93 different digital devices over many years.
In my opinion when you're setting up a digital front end, it is a lot like setting up an analogue front end, there are lots of little details needed to accomplish a spectacular digital front end. I believe that everything starts at your receptacle. Replacing the original receptacle with an upgraded receptacle and then adding an upgraded power cord from that receptacle to a quality conditioner is the foundation to every system. Once this foundation is set up properly then changes to your digital front end should be easy to detect. If you cannot hear any differences when you are swapping out digital devices, streamers/server or DACs then something is wrong with your system.
Back to the original question, absolutely you should be able to hear differences between one streamer and another streamer. I have tested many different streamers/servers at many different price points and the top streamers/servers in the world definitely create a more holographic image when they are properly set up. The problem is that to get to this level every single small detail in your set up makes a huge difference. The digital cable from the DAC to the streamer can make a huge difference. The Ethernet cable or the quality of the Ethernet cable from the streamer to the router can make a huge difference. The quality of the router also makes a huge difference and as I said originally having a great foundation, upgraded receptacle, upgraded power cord and spectacular conditioner adds up to a true reference system. The closer you get to having the system set up proper, the more you will hear the differences from one server to another server.
Cheers,