I do like my 920+. It does the job and generally does it well. Like most nas you are mainly paying for software more than the hardware specs. If you want to go faster and not break the budget, you could always go the custom way. Truenas scale or something like that. Its not as easy to setup channels and other containers but is totally doable. If your looking for a ready to use product and just pop in some drives, the j4125 chip in the 920+ will do a decent job and is cheap to run.
I am sure others have some good experiences with other brands. But the only nas I have ever owned is synology. I also have a test system setup with truenas scale. I am waiting for bluefin release of truenas scale to take full advantage of a intel 12400 processor. If you wanted me to compare the speed difference between the two. Its noticeable, but not so much so to where I would say forget the DS920+.

