I totally get where you're coming from
@Nuclear_Creeper0 - it was a simpler time! I recall way back when, when most mods used their own power systems with no interchangeability - at the time it was... not fun.
That said, for me the slight homogenisation that came with everything using RF did lead to things being a little duller at the same time, and I'm actually at the point now where I'm quite looking forward to having to use all different power sources for different mods again! But, I'm a weirdo
For me its the same as
@Inaeo: Thaumcraft. Not just the mechanics of the recent one, but the...
feel, and the lore, of all of them (well, as far back as Thaumcraft 2, which was the earliest one I played with). There was something wonderful about it, it felt like it was so rich in lore and full of character, like it was lifted from the fantasy setting of some books or something! All iterations have had that, to a greater or lesser degree, and the world of Minecraft will be diminished for not having a Thaumcraft.