Enlightening vs. Super Cubes

On a whim, I used about 5 enlightening cubes on my bossing wand. It was at legendary potential with lines of 20% bossing, 20% bossing, ignore 40% since like February. After the 5 enlightening cubes, it came out to 40% bossing, 30% bossing, and (ugh) 9% STR. The extra bossing made a huuuge difference (seems like 30% extra bossing makes much more of a damage increase than 30% ignore, but this won't go in my favor if facing a boss like cht or pink bean due to their high PDR). It seems like enlightening cubes only help an item out if it is already at legendary potential, since it sucked badly for the other equips I've used it on which happened to be rare/epic/unique.

This is what I was thinking also, but I was wondering if there was a difference in the chance to upgrade to the next tier between the two cubes. I think I'm leaning towards super cubes until I hit unique or legendary.