I've been mostly playing solo since Big Reactors has been around. I have a 7x7x7 with the same internal layout as malicious_bloke's, i.e. diamond blocks among the fuel rods and resonant ender around the outside. It has a peak output of 11.6 kRF/t, and I haven't needed more than that yet, but I haven't got around to setting up laser drills yet, either. I tried using MFR's programmable rednet controller to adjust the fuel rods, which wasn't hard to do, but because I wasn't using huge amounts of RF, the reactor was never getting hot enough to keep up a good fuel efficiency, so I stopped doing that. Once I get my laser drills set up, that may be a thing to revisit.
I still want to try cryotheum, see if I can squeeze a few more RF out of the 7-cube before getting on with the next phase of construction.