I saw that too...How can something using Electron be highly efficient? Maybe they are talking about the interface and not the system resources the app uses.
Both interface and performance actually. I have a library of about 1000+ songs and it barely takes anymore than 130 mb of RAM for me. This is actually better than some native c# music players that I used before I made this. And CPU usage is very light.
Clementine doesn't use Electron and consumes more of my memory and UI is ugly. Before we start talking about resources maybe we should compare other music players on the market.
There isn't really one inherently; a music player like foobar2000 only takes a few MB of memory even with many plugins. That doesn't mean Clementine and Winamp haven't found ways to waste resources that aren't loading a full Chromium instance (after all, Chromium is pretty efficient considering what it actually brings to the table.)
As a matter of fact(but not scientifically accurate), chromium-based browsers were consuming twice as much RAM on Win than on Linux whenever I checked.
High quality on the web player should be 256kbps AAC, so it should have no audible issues. That said, I find the web player absolutely horrible to use.
The desktop Electron app may be a bit of a pig, but on the other hand it runs on Windows, mac OS and Linux with very few issues, so I'll accept that trade-off.
I don't have Spotify premium - so the quality is 128 kbps.
The app works pretty fine, but is absolutely slow on my (old and quite underpowered) living room PC. But on the other hand it is just a media player...
The quality was the deciding factor for me to use the Spotify app.