I have experienced installing cables and busbars. The only thing I can say is that busbars in busways are not really flexible. When it comes to speed of installation, you will spend almost the same manhour installing busbar and installing cables. When it comes to safety, I would prefer cable to busbar. But it is up to you, if your business is getting commission for selling busway solution, then, you really have to believe that this is the best solution. Otherwise, you won’t be able to sell it.
It looks like you have experience using busbars. Why you say it is not flexible: you means products during installation or during utilization?
For my project you feel cable would be cheaper.