The GFX 100S is a recent model that features in the current product line-up of Fujifilm. In contrast, the K-70 has been discontinued (but can be found pre-owned on ebay ). There has not been a direct replacement model for the K-70 from Pentax. Further information on the features and operation of the GFX 100S and K-70 can be found, respectively, in the Fujifilm GFX 100S Manual (free pdf) or the online Pentax K-70 Manual.