I haven't seen magtubes mentioned here yet. When I built the item-handling system in the lair on my server, I decided to use them pretty much everywhere. The last time I built a system like this (big factory & storage area, tubes EVERYWHERE) magtubes weren't in yet, and the lag was noticable when even a moderate number of items were coming in.
This one, the magtubes get stuff out of the system so fast, my frame quarry can dump every block in a chunk into the system in the space of 5 minutes or so with no lag at all. And that's with a factory recirculating overflow. The accelerators don't take too much blutricity, and the tubes themselves are just copper, obsidian, and glass, which I normally have too much of, anyway.