Nah, lategame powergen is easy. You can get 1200 EU/t from 12 MOX cells without having to dick around with pressure vessel reactors or the under-development heat system. Just preheat the reactor to 80ish% with one (or two if you're ballsy) reflectors and then take them out. Once I get my three reactors migrated to plutonium, I'll be making around 3600 EU/t which is in the same league as the old LZH-condensator beasts but without the lapis usage. I just need to figure out an auto-preheat mechanism so I can automate turning them on/off and refueling.
The only downside is that you have to centrifuge 324 depleted uranium cells to get your starter plutonium. I currently have my reactors burning uranium cells just to get plutonium. Blutonium is weaksauce and I refuse to use it with oredict. As far as I can tell though, you get the plutonium back when you centrifuge depleted mox cells while the uranium used to make them is consumed.
While you wait for your plutonium though, a great mid-game step is Railcraft boilers. You get 400 EU/t for each max size HP boiler by outputting to two RC steam turbines each. Side note, a single fluiduct can handle the output of the boiler and you don't even have to use a servo. I would recommend liquid fueled since solid fuel can be annoying. I just emptied 3.5 large oil springs into a max size iron tank (full at 10k buckets). I have one boiler powering four refineries and another outputting to turbines. I could probably add another two boilers and it'd still be enough fuel to run basically forever. But wait, there's a downside. That's a butt-ton of steel and it'd take way too long to make. Just make refined iron with an induction smelter, 1 iron ingot, and 2 coal dust.
