For me Factorization is just an awesome mod. I usually build the slag furnace about my fourth or fifth block. It is just an useful thing. Yes it takes double the fuel to run at first but being able to get bonus stone as well as a chance of more ore is worth it. Taking eight copper ore, as example, and getting eleven is nice. Yeah getting nine diamonds can seem to be a PITA but for the 300% increase in ore is so worth it. The mirrors look rather cool and don't detract at all. Also, incase no one noticed, but one episode of Direwolf's SMP had steam being used by Factorization so yes Molly you can have more power if you so wish it.
Having the furnace heater is just great as it can help make the slag as well as regular furnace free to use. As in no EU/MJ/Blue power. Yes you need mirror and a solar generator but the nice thing is it can be very compact. One heater with about ten mirrors can run a regular furnace, slag furnace and crystalizer. Crystalizers also do more then ores. Put in lime green dye and milk, wait a bit, bingo slimeballs! Only thing I wish was the slag furnace be able to smelt more ores.
Having the furnace heater is just great as it can help make the slag as well as regular furnace free to use. As in no EU/MJ/Blue power. Yes you need mirror and a solar generator but the nice thing is it can be very compact. One heater with about ten mirrors can run a regular furnace, slag furnace and crystalizer. Crystalizers also do more then ores. Put in lime green dye and milk, wait a bit, bingo slimeballs! Only thing I wish was the slag furnace be able to smelt more ores.