Honestly, I haven’t used Habitat Quality much myself so don’t have wisdom about its usage to share. But I can point you to a study that was done by colleagues at WWF, which used habitat quality to look at tiger habitat, including doing calibration against observations:
Bhagabati et al. 2014, Ecosystem services reinforce Sumatran tiger conservation in land use plans
http://dx.doi.org/10.1016/j.biocon.2013.11.010
There may be others too, @Lara, it could be useful to search through our publications database.
~ Stacie