These MFD's are a really nice addition to any simpit. I've seen them used as button boxes for racers but for me they're used as intended, for military flight Sims namely DCS World.
They are made of a study plastic which has a nice feel to it, all the buttons are backlit (controlable by T.A.R.G.E.T possibility but i haven't tried) making night time flying easier. I fly exclusively in VR but have no problem finding the buttons i need.
They work out of the box on the 2 modules i own that incorporates MFD's, the Hornet and the Harrier but the main aircraft i fly is the Tomcat.
I've got these mapped to lots of various functions from HUD modes, Nav modes to lights and NVGs and they perform flawlessly.
They can be mounted in a simpit from what i gather however i have them on the desk on either side of my stick. I haven't experienced issues with them sliding around like i believe others have experienced.
All in all these are a cheap-ish way to add more controls and more immersion to your sim experience. I would very much recommended them