@Omicron your post describes exactly why i put RP2 Blutricity in the category i did. It's the most similar to how real life electricity distribution works... Want to transfer power for a long distance? Up the voltage. Want more efficient but short distance power transfer? Low voltage, high amps. Electricity balancing itself along a system where each battery is connected is how real life (rechargeable) battery lines work. After all, if it's a closed system, it will try to find equilibrium, as per the law of thermodynamics. Energy flows from the point of highest density to the point of lowest density. Which is very cool if you're an electric engineer, but less so if you're just trying to play your game.
RP2 Blutricity makes you get more involved into how you're producing your energy. You need to keep track of the voltage in your cables, to make sure if you need or don't need a transformer there (which in RP2 is just sticking a battery there), different cabling for long distance transfer (but not necessarily high energy!).
In IC2 is simple. Are your packets smaller than 1EU? Tin cable. Are your packets smaller than 32 EU? Copper. Are your packets smaller than 128? Gold. Are your packets smaller than 512? Fibre Glass. Are your packets higher than 512? HV Cable.
BAM! Solved. Energy loss only ever starts being a problem with the lowest tier machines, since 99% of the time, you'll be generating your energy inside 40 blocks from your factory area.
In BC2, it's also simple. Cobble makes you lose a lot of power, stone a little bit less, and then gold is the best. Except when you get TE, which gives us Redstone pipes. Very simple, don't generate a lot of headache.
What most players want? They want simplicity! They know their machines need power, they know how to generate the power, they know how to transfer the power. And that's all they want to know, well, most of them anyway. They don't care about why there's energy loss, or why certain cables explode, they think it's just a balance thing. They don't want to have to plan an energy grid, where you set up transformers to turn the low voltage high AMP generated by turbines into HV/LA current used to transfer power, and then another transformer to power their machines. Hell, they don't even want to have their energy generation to occur in a separate location, if possible! That's why most of the energy generation machines are 1 block strcutures.
Personally, i'd like a liiiiittle bit more complexity involved. Not a lot, just a little bit. For starters, make it so that you can't connect machines directly to the engines. Thaat's dumb. Make it so that you always have to have a transformer/battery box between your machines and the engines. It just makes sense. Engines don't always output energy at the same rates, voltage or amperage, they vary, a lot. That's why you need both Capacitors and Transformers, to make that variable current into something stable. There's also the fact that engines usually output in DC and power transfer is AC. So i'd add those blocks, capacitors that turn DC into AC, and transformers, which can manipulate voltage. I'd get rid of multiple types of cabling altogether, except for LV/DC(Direct Current)/HV.
In real life, copper vs gold cabling for energy transfer don't equal to that huge of a difference, based on the costs involved. It's DATA loss that's the real problem with copper vs gold vs fiber cable, not power. The difference is offset by making the transfer more efficient by using extreme high voltage to transfer between the power plant to your house/factory.
A good system i think would be:
Engine -> DC Cable -> Capacitor -> Transformer -> HV Cable -> LV Transformer -> LV Cable -> Machines. I'd also make every engine a Multiblock structure, because, really, small engines output a piddly amount of power, enough to light a house for a couple of hours, at the most. Nothing industrial level. You want an industry, then you need to build an industry. YEAH. Most machines should be Multiblock as well, with advantages to them, like being able to smelt multiple stacks of the same material at once, work faster as they get bigger, etc... I really like Railcraft's approach to this, with the Boilers, Coke Ovens, etc... But, yeah, i think adding complexity to the system is a good thing. You shouldn't be able to uproot a Industry without having a load of material ready already. Not Gregtech level of materials needed, mind you. Again, i think Railcraft has a nice balance going for it. I would be very interested in seeing what CovertJaguar would come up with if he thought up his own energy generation system, instead of using Buildcraft.