Rationale for the TL-PA9020P: 2000Mbps WHERE????
I must confess that I do not really understand what this claim of "2000Mbps" even means: WHERE is this speed achieved? Between what two ... points? Surely, given that the Ethernet ports are only rated 1000Mbps, no such speed can EVER be achieved between any two devices connected to the Ethernet ports.
Again, WHERE is this (theoretical) speed achieved? what does the "2000Mbps" mean?
This is a result of the standard naming used by HomePlug AV/2 - reason being that installing an adapter slower than your existing adapters standard will slow your entire powerline network down to match the speed of the slowest adapter.
The speed is based on the technical capabilities of the technology and is essentially a cacluation of what could be achieved in an ideal situation with no interference; similar to the speeds that you see advertised for potential wireless speeds.
It is highly unlikely that you would see the full link rate and need a 2.5Gbps connection, hence the powerline adapters only include gigabit ports.
See the following footnote on the product overview page: 
