I HIGHLY prefer RP over BC for 95% of my tasks. Some of the things I use bc for are liquid transportation, long distance item transportation (if "BC" also includes tele pipes addon). BC is also useful for using with Forestry, one of my favorite mods.
About your question on the quarries, it is simple. Frame quarry! Why? Because frame quarries
-don't need power
-a lot more efficient
-mobile
-doesn't leave behind ugly orange frame that takes years to break
-can be made huge
-look cooler, and are funner :D