I think that they are really good for 2D games (especially if you want to support Android and iOS) and that they perform very well in renderings and animations.
However I think that libGDX support for audio can be improved a bit.
Don’t get me wrong: libGDX has a good support for audio but I miss the days when I played around with Pure Data.
So I decided to write a small libGDX backend for libpd, the famous library that turns Pure Data into an embeddable audio synthesis library.
The repository is called pd-for-libgdx and you can find it in my github: https://github.com/manhluong/pd-for-libgdx.
It’s open source, Apache v 2.0.
The backend is still a work in progress (actually it supports only Android and iOS) but it already let you play sounds, like in the pianotest project:
This backend is designed to be used from source, cloning the repository and adding the projects and dependencies to your Eclipse workspace.
Also, keep in mind that I am still using the old way how libGDX handle the projects. That means no Gradle, for now.
Please read futher if you want to know how to use the backend and for some technical details about libGDX.