Distributions of black hole mass estimates (M_BH), reddening-corrected bolometric luminosities L_bol and Eddington ratios λ_Edd for the control and red QSO samples. Only M_BH estimates from spectra with quality tag 0 are considered, which comprise 90% of our entire sample. A Gaussian kernel-density estimator (KDE) with a bandwidth of 0.3 is used to display these distributions. With exception of the differences in the bolometric luminosity distributions, where significance is weak, no significant differences are found between the red and the control QSOs in these parameters. The significance of the difference between the two distributions (KS-test p-value) is reported below. The p-values were computed using the estimates reported by Rakshit et al. (2020) (M_BH and λ_Edd), and using the bootstrapped KS-test for the L_bol, where the posterior distributions from the MCMC-based SED fitting are compared and therefore uncertainties could be calculated.