said by Guspaz:
Yeah, the only way to know is to actually test it. There is a ton of variation in this. Different models from different brands perform very differently, and the quality of the wiring, the location in the house, all of this can have a big impact.
Most adapters include a utility that shows actual sync rate. This is what I see for my 500Mbit Zyxel adapters. The Ethernet interface on them is Gigabit so I can actually pull through more than 100Mbit/s. Some are only 100, which limits things. Either way, the Valet M10 we have use as a supplementary AP in the warehouse that's connected to the bridge only has a 100Mbit Ethernet port anyway. The adapters serve their purpose and they serve them rather well.
Anything powerline is going to be more than enough for most
Internet connections. It only starts to potentially become an issue when you're talking about moving a lot of data across the network.