I know that the web GUI is not used that much and development is also stagnating. I stumbled upon it a few days ago and so far I think it's good. It does what it's supposed to.
The transfers are running fine.
What I'm missing is the information about the running jobs or the progress, which remotes are involved. In my case, I started several jobs via Explorer. In the dashboard or in the progress window, it can no longer be assigned to which remote this job belongs.
I found this tip very useful.