Yeah, I encountered projectred while I was paying tekkit, and only encountered energistics and buildcraft later. The advantage that projectred's piping system has is they are about as cheep and simple to make as buildcraft pipes, but include some of the functionality you find in energistics. Where Energistics requires you to build through several different levels of tech, is costly in terms of resources and power and is not easily compatible with early game systems. For a lot of quest-based modpacks this often means a double up between buildcraft and energistics, where once you get to energistics it's more cost effective to completely remove the older system. Especially if the older system is buildcraft.
With the number of times my game hit massive lagspikes or crashes cause something went weird in the buildcraft piping I found myself swearing "As soon as I hit Energistics, these things are coming out!"
Saying that, this comes back to my earlier post. There are plenty of alternatives for logistics pipes already out there. Which is why these robots seam so adorable. I would totally accept robot based logistics over pipe based, it could easily be just as fast, would take up less space and doesn't result in a bunch of 'items' flying loose around the world individually (just a handful of bots instead)
I also thought of another use for the robots. This is meant to be Build Craft right? How about adding in less OP variation of worldedit. Give us a means to create templates of oblongs, cylanders, spheres and other regular shapes at any size, define it as "Hollow" or "x block" then place that on a landmark to tell the robots to mine/dig/build as required. I mean the blueprints as they currently work are essentially cut and paste, the only other parts of worldedit are shape generation, brushes and block swapping.