I'm not exactly looking for uniqueness in it now but rather, a point to use it besides liking it (for those that likes it) enough to want to use it.
Last time, I bear with IC2 because of the Induction Furnace. Now I have Mekanism's Elite Factory - Smelting with 7 slots for processing, x9 speed and energy efficiency upgrade for that. Macerator with overclockers? Elite Factories again.
Power storage? A lot of other mods does it better. And almost (if not all) allows moving the storage itself and keeping the power in it.
Item transportation? None in IC2.
Facade/Microblocks/Aesthetic stuffs? I know IC2 has CFoam but in my own opinion, other mods has it beat.
I prefer BC's facades over IC2's CFoam for couple of reasons. The facade is removable without breaking the pipe itself. Pipe plug can be used together with facades to create nice looking walls that doesn't connect to other inventories/machines if pipe plug is installed.
TE3 supports FMP now. Which is also removable without breaking the cables, can be used to separate the cables from connecting to parallel cables.
Ender IO's painter does a superb job, in fact I would want to argue it does cable hiding the best out of all the competitors since you can access the cables without removing the facade.
Now, if CFoam can be removed without breaking the cables, please do correct me.
Nanosuit, nice suit be to frank. I will not compare it to MPS because MPS is a mod dedicated to power suits and weaponry so in my opinion would be unfair against IC2 since IC2 isn't just about the Nano suit and Nano sword. When comparing it to it's "competitors", I would say it has no equal.
Nano sword. Was nice but I always dislike the fact you can't block with it, might have changed to a key toggle and allows you to block with it now. Drains power when you turn it on, regardless if you are using it or not. I do not like that. Nearest competition would be the recent addition from TE3 in the form of Redstone Arsenal's Flux Sword. Great weapon where you can use it like a regular iron sword (or slightly better?) or you can activate Flux mode and deals more damage at the cost of higher power requirement. It is also able to accept enchantment which is a great. Sharpness IV + Flux mode is awesome.
Jetpack. Mekanism has it too and both work pretty similar.
Mining Laser. Has no equal and I can say I have pretty good experience with it and say it is a nifty tool. Just don't try to change setting while in base.
Drill/Chainsaw. I would not compare TiCo with it, again on the basis that TiCo specializes in tools and that would be unfair against IC2. So I would say that it is unique for IC2 as a mod by itself. Redstone Arsenal does provide pickaxe and axe but from my own experience, they do not fair as well as the IC2's counterparts. I might be using them wrong, so do correct me.
Lastly, IC2 Crops. Or rather, cropsticks. I like those little buggers a lot. I didn't play with crossbreeding much but I do like how compact it allows my farm to be when I had IC2 installed. Sugarcane not requiring to be beside water. Wheat not replanting. Netherwarts on dirt! Melons and Pumpkins in 1x1x1 area! So you can fill the entire 9x9 farm with all Melons and Pumpkins for maximum efficient use of land! They would with MFR's Harvester too! I do wish IC2 team would develop IC2 Crops as an optional addon and not requiring IC2 dependency.