The difference between this pack and FTB Ultimate was ...
As you haven't quoted a post your replying to and this thread covers all the FTB mod packs I will give a general reply from the little I know - the DW20 pack (for instance) modifies recipes to balance the packs, some mods make getting some items very easy and others make getting items very hard. Things like ore generation, one mod may rely on an ore to be scarce or hard to process and another mod adds a heavy supply of the ore or makes processing easier and the crafting of the original item that was meant to be hard to craft become simple. So the solution is to alter the recipe, this is usually (I believe always) done in consultation with the original developer.
As to the wiki - for quite a while there have been 2 or 3 alternate recipes for some item on wiki, they will simply state "with mod-x installed" or similar, like the example below, it is not that complicated
http://ftbwiki.org/Grinder_(MineFactory_Reloaded)