For me, the appeal of AE(2) and RS is all about integrated autocrafting. In large modpacks with many complex mods with long crafting chains, repeatedly crafting the same complex thing becomes a chore. I don't think I can play a tech mod any more without something like these mods provide. I also tend to automate crafting of pretty much everything eventually, and I prefer compact solutions like AE2 or RS provide to more space-devouring solutions like LP.
For storage, there are alternatives. EnderIO, RFTools, Storage Drawers, Extra Utilities all provide feasible storage solutions. For autocrafting, LP is good for smaller setups but I don't see anything that can replace AE2 or RS if your systems get large enough.