1)

http://www.red3d.com/cwr/boids/

2)
https://github.com/recastnavigation/recastnavigation

Which one do you prefer to use for collision avoidance?
DetourCrowd by Mikko or Red3D (Craig Reynoids)

I already setup Recast, but Craig's solution is quite simple and elegant

Why are you asking? Why the survey of strangers on the Internet?

If one is better suited for you and your needs, go for it. If the other, go for it instead.

What one person needs may not be what another person needs, so surveys about being 'better' often don't offer much benefit.