Digital elevation models (DEMs) are essential for many governmental, scientific, and commercial applications. Recently, with the release of several new products, the availability and quality of global 30 m DEMs (GDEMs) have improved considerably. Here, we present a validation of five original GDEMs (e.g., Copernicus GLO-30) and four bare-earth GDEMs, including FathomDEM and GEDTM, two recently developed products with enhanced artefact removal that are expected to outperform existing GDEMs. We evaluated the accuracy of elevation, terrain slope, surface ruggedness, and delineated stream network. Our results showed differences between the two categories of GDEMs, with bare-earth GDEMs being substantially more accurate than original GDEMs over Czechia. The highest accuracy was achieved by the FathomDEM, followed by GEDTM and FABDEM. The difference was most pronounced in forests, where the FathomDEM yielded an RMSE of 2.7 m, approximately 2-4 m lower than other bare-earth GDEMs and 7-11 m lower than the original GDEMs. We also observed a noticeable effect of land cover, terrain slope, and their interaction on the accuracy of elevation and derived terrain characteristics, with all metrics exhibiting the lowest accuracy in forested areas. Bare-earth GDEMs performed better in estimating slope, ruggedness, and particularly in delineating stream networks; however, original GDEMs can still be effectively used to derive terrain characteristics, and perform comparably well, except in forests on gentle to moderate slopes. Overall, our findings show that FathomDEM maintains the highest and most consistent accuracy across diverse conditions, constituting a major milestone in global terrain mapping.