Thinking about it, if you're feeding, say, a quarry into an enderchest, then you'd be looking at 1 energy to pull an ore out of the chest and into the network, 1 to pull it from the network and put it in an induction smelter, and then a maximum of 3 energy to pull the two ingots and one potential rich slag from the smelter and back into the network, for a total maximum of 5 energy per processing operation (but only 4 90-95% of the time). If you've got a quarry running at 5 blocks per second (which I believe is about where it ends up with 50 MJ/t behind it), you're still only looking at a maximum of 25 units per second, or 1.2 per tick. That's like 0.25 MJ/t, when you're already going to be using 8 for a smelter and a pulverizer feeding it sand. If you use macerators and electric furnaces instead, then you'd be looking at 8 per ore (one less because no rich slag, four more for pulling two items out of the macerator and putting two into the furnace), but that's still not all that much. With a TE system, you'd have to get past 160 blocks per second to have the I/O cost equal the amount of MJ you're already feeding into your machines, and even then that's just one industrial steam engine, and pretending that 99% of those blocks aren't just cobblestone (which will only cost 1 energy to pull in, since they don't need processing). Plus that MJ can always be converted into EU for a further boost in efficiency.
Really, unless the numbers the wiki gives are wrong, or there's a whole lot of power leakage going on somewhere in the process that my experience-less theorycrafting doesn't account for, I don't think it's that big of a deal.