Hi,
First if you see and compare review and active installation of two plugin
– Gutenberg
– https://www.ads-software.com/plugins/classic-editor/
Then you will get idea about this plugin. Main thing it should not come in default WordPress version. you can just recommend to use. because very less community who it is liking and using.
If you want to see quality of builder then you can compare with Elementor,Divi,Avada,Visual composer etc.
Well this plugin is lightweight right now. but this concept will be false after some years because right now this plugin is in development process and early stage. after number of release it will be full rich feature it will be also heavy.
Thanks.