However, it should take into account that the performance of a CPL kit are directly impacted by your electrical system, so if your system like home 25-30 years, well it is inevitably less impressive than in a new house. It is however much faster than traditional WiFi.
I was unpacking, transfer rates to my NAS which were 5MB / s to 10MB / s, it is not huge, but for the price and saw my electrical installation I think it is frankly not all bad . However, I have since made days firmware kits via the manual supplied by TP-LINK and this has actually enabled a significant improvement in signal-term stability and the level of transfer rate.
In short, at this price do not expect beasts racing, but if you are just viewing videos FHD, video games and NAS transfers, it should amply suffice.