There is nothing realistic about how IC handles electricity.
- gold is more conductive than copper, not less
- copper is more conductive than tin, not less
- glass fiber is not conductive AT ALL and is not made of diamonds
Even ignoring these inconsistencies, the wiring system is not very balanced. How often do you see anything BUT glass fiber cable in builds? Only people making high-end nuclear reactors or playing gregtech have any incentive to use anything but glass fiber cable.
Eloraam has actually created a system that's somewhat realistic.
I agree here, although her decisions on how to model wiring ended up with wiring that works very well for small distances and very poorly for large distances, and we never really saw a proposed resolution to that.
King lemming saw that realistic doesn mean 'fun' perse and created a cabling system that's both fun and easy on the server cpu. All hail King Lemming!
Redstone Energy conduits are great and actually useful, which is such a novel idea for moving buildcraft power. KL basically salvaged the entire Buildcraft tech tree with a few machines. Awesome.
There are other power systems out there, though. Steam is great, overall (although I wish CJ would stop nerfing everything that works well; I really am not sure what he actually wants us to do to make steam!) and UE's powergen options are fun (though... they have bizarre default values for conversions to IC2 energy; gotta fix that).
Both Railcraft and Atomic Science turn power production into huge multi-block affairs with lots of ancillary automation and a bunch of fun and subtle design choices. For example, the exact size and nature of your boilers can be a matter of some debate depending on what you're doing. Similarly, there is a surprisingly interesting design choices on Atomic Science nuclear reactors and Fusion Reactors.
I don't like the trend we've all run into of "perpetual power". I wish high-end Power was an occasional chore. In this, Gregtech does a better job than most.