I just got around attaching the side bags to my BS6.
I have to say they look quite fancy. The big pouch has a smaller one attached to it and the big one has a zipper while the small one has a magnetic clip-type knob.
The entire thing is then covered and attached with a buckle.
The bag gets fixed by the 4 or rather 3 small Hex Key screws that hold the plastic side cover. The top 2 and one of the lower ones are easy to put in but the 4th is nearly impossible to attach – but 3 hold it in place just fine.
The OEM toolkit fits just fine with room to spare for e.g. a torch and some more smallish gimmicks.
The smaller pouch can be used for papers you need (in India that would be insurance proof and pollution control) without the need to gather them from under the seat in a traffic check.
So it is quite useful and while I think you ever only need one bags for the left and right side are available.