GNRs (AGNRs) have attracted very much interest lately, due to their anticipated magnetic properties, although their presence in finite nanographenes (NGRs) has been predicted long time ago. However, the significance and importance of end states for AGNRs was recognized only recently , after the pioneering bottom-up synthesis of atomically precise AGNRs of finite lengths L with short zigzag ends, and their characterization by scanning tunnelling microscopy (STM) and spectroscopy (STS). Clearly no end states appear in the common infinite AGNRs fabricated by the usual top-bottom techniques, which are theoretically described by periodic boundary conditions at their two ends . The new developments have brought to the forefront new concepts and properties such as the "bulk band gaps" ΔΕac (or Δac ) i.e., the energy gaps between delocalized states, and the energy separation of the zigzag-end-localized "end-states", denoted here by (ΔΕzz) (or Δzz ), thus increasing both quantity and quality of key properties to be rationalized, understood, or interrelated at the atomic scale. At the same time, despite the increased complexity, such advances have also allowed the study of the L-dependence of key-quantities such as the bandgaps (both, ΔΕac and ΔΕzz), conductivity, aromaticity , and even Raman spectra. The L-dependence studies revealed that the changes in such properties versus length are not always gradual (or smooth). The presence of a metal-insulator-like phase transition at a critical length Lc was advocated by two different recent works, Lawrence et al. and Zdetsis et al. , almost simultaneously. However, the two works have offered different assessments and interpretations for the nature of the transition and magnetism, as well as the value of Lc. This is not something new or unusual in a rapidly grown pioneering field like this , and this is not the only existing "discrepancy". Other conflicting (or conflicting-looking) results (experimental and theoretical) include the magnitude and nature of the bandgaps , the existence and nature of magnetism in the edge states , as well as the magnitude of the substrate influence on these properties. For example, the magnitude of the bandgap for the 5-AGNRs has been measured by (at least) three different groups to be 0.85eV , 2.8 eV , and 0.1 eV respectively, while the theoretical values vary from 0.1 eV 1 to 1.7 eV. For the 7-AGNRs the measured values of ΔΕzz vary between 1.9 eV and 2.5 eV , whereas the measured ΔΕac values range from 2.3 eV to 3.2 eV , overlapping significantly with the range of ΔΕzz. Thus, the unambiguous distinction between ΔΕac and ΔΕzz is another subtle point together with the bridging of the measured and calculated ΔΕac values, which also vary widely from 2.3 eV to 3.7 eV. Some of the (different) measured or calculated values correspond to AGNRs of different length, but in the literature the quoted values are usually given without reference to the actual length which is, thus, treated as a hidden variable. However, the biggest problem seems to be the large difference between the measured values of the gap(s) in relation to the "official" theoretical values obtained by the GW method , which are widely recognized as an almost universal point of reference. Such large differences (almost ~1.5 eV for the 7-AGNRs) between experimental and theoretical GW gaps (ΔΕac) are usually attributed to the screening from the metallic (Au) substrate ΔEsb, even though identical values of gap (within the experimental uncertainties) have been obtained for AGNRs grown on non-metallic substrates, such as NaCl 6 and MgO . This is clearly (at least) problematic. As a result, it appears that there are several conflicting results and interpretations or high-braw "solutions" about the STS gaps, although the real solution could be much simpler (but not always obvious), as could be possibly argued on the basis of Occam's principle. Along these lines the present work aims at deciphering all these subtle points, also including the confusion in distinguishing between ΔΕac and ΔΕzz gaps.