We have embarked on the challenging task to characterize the spectra of a large sample of Super-Jupiters, Brown Dwarfs, and free floating planets using ground-based high-dispersion spectroscopy at high precision, retrieving the abundances of many spectroscopically active atoms, molecules and isotopologues, deriving atmospheric temperature-pressure profiles and constraining the presence of clouds. We have already analysed dozens of objects and it is now time to analyse trends in their chemistry and explain them in terms of atmospheric processes and possible formation and evolutionary pathways. In addition, some of the spectra reach S/n>100 per resolution element, equal or better than the best exoplanet spectra we can ever expect for more challenging targets - even with the ELT. What have we learned from the very complex analysis techniques and what limits their interpretation?