Seems like a couple of blinky balancers lots easier to use than the two balance outlets on the Duo....guess you need four of them to balance 2 packs but they are pretty convenient.
They may be more convinient, but you loose out on the safety side of the house.
Chargers with integrated balancers are able to verify that you specified the correct number of cells and in addition they monitor the voltage on individual cells and stop the charge if they are too high/low indicating that something is wrong with the pack.
In this case, I would rather deal with the extra work of using the integrated ports.. :-