Multiple UAVs for research project

I would like to know your opinion about a problem I am facing.

I am thinking about alternatives for the hardware/software architecture for our drones in order to try out something different from what we have now.

If you would be able to start your own research lab with UAVs and especially multirotor UAVs (quadrotors in particular), which platform would you adopt?
We want to operate INDOOR

Note1: The research is about multirobot formation control, onboard computer vision, navigation in cluttered environment, onboard computing, decentralized estimation/control, interaction with the environment etc.

Note2: when I say platform I mean software/middleware/hardware

Note3: We already have available a Motion Capture System (Vicon/Optitrack)

Is Ardupilot able to do the job here? Is it feasible to connect multiple drones and control them over ROS?
Another option is of course to use PX4 but I am getting more and more convinced that maybe ardupilot would be a better choice.

Do you know about alternatives? What would you choose?

Thanks for your thoughts