Hello!
Omicron asked me to post this one from another thread I replied in.
It's a 6-chamber that may be a good compromise between Blackpalt's and Zombie's design in the list.. it produces more EU/t than Blackpalt's and uses less Uranium / Plutonium than Zombie's, so it may be worth looking at.
It's 100% thermally stable (+-0 heating), so once you have it heated up to 85%, it STAYS there with no automation required.
Heat-up is swift if you remove the overclocked vents, takes me about 40 seconds or so to boot it up from zero.
Output COLD: 270 EU/t
Output HOT: 1,177 EU/t
Efficiency 3.86
(in case I missed a similar design in all the posts, Omicron feel free to this response of mine