1 CP2013 had a hacking system. It was pretty cool if prone to GM fiat. But CP2020 had NetRunning. In this system, an entire ‘Run happened in a single turn in real space. To make matters worse, all the rest of the group did in cyberspace was slow down the NetRunner. Because of this, I ruled that either the entire group would be NetRunners or none of the PCs would be. NetRunning was a critical part of the setting, so I made sure the PCs had access to a friendly, reliable NetRunner (usually one of the first friends rolled during Lifepath). Other games have had this issue as well, Mekton, various Star Trek games and to a lesser extent, games that needed mass combat rules. In each case, you either had to have all the players involved in both the street-level system and the special subsystem or none of them. From this I learned to make sure that all the PCs are operating in the same arena/level with my designs.