I know this thread is over a week old, but just let me drop in and say that the new version of EE, v6, has had MASSIVE rebalancing. For instance, most Philosopher Stone transmutations are gone. But that's not just it. Cobble was devalued to dirt-level, 1 EMC. Diamond was boosted to 8192 EMC. You need 128 stacks of cobble to make a single diamond now. Of course, you can still use iron and gold (16:1 and 4:1 respectively) to transmute diamond using the Transmutation Tablet, but those aren't the most readily available resources either. I'd say getting 4 stacks of gold is almost as time-consuming as getting a stack of diamonds.
In general, EE6 seems to be much more balanced when used in tandem with other mods.
Ah, but who am I to judge? I use Thaumcraft, which has the insanely low Dirt-Diamond conversion rate, about 300:1. On the plus side, Thaumcraft is not exactly the most unbalanced mod aside from duplicating.
The problem with both Thaumcraft and EqEx is that they play in a totally different universe than IC2. And IC2 is one of the more diamond-consuming mods but still in most mods diamonds are endgame items, but not in Thaumcraft or EqEx. They both give you some alternative materials for endgame. v6 changed nothing at this concept. And the Relays, Collectors and Condensers are just what they are, incredible powerfull. They are quite balanced in terms of EE itself, but they are quite of if you combine it with other mods that still use diamonds as endgame components.