I just started testing the PowerLine products for use in our production environment. Unfortunately, we have run into two places where the products fall short of our operating standards:
1) The only way to power these devices is directly via the mains. We put all our networking equipment on UPSes as a matter of policy, because power in our area is less than 100% reliable. If these devices could also take power via PoE or some other external source, then in a power outage they would continue to work.
2) We use dual-band APs everywere, because 2.4GHz is congested to the point of being unusable in the multi-unit environments that we serve.
In short: we would find these PowerLine devices much more useful if they had more powering options, and included a 5GHz AC radio.