I've used homeplugs for many many years now, got 5 x av200s around the house. One of them has finally died so was looking for a replacement, and av200s are no more, but I was pleased to read that they are all backwards compatible... From the FAQ... TP-LINK AV200, AV500, AV600 Powerline adapters adopted HomePlug AV Standard, so they are compatible with each other. The TP-LINK AV1200 adapters adopt HomePlug AV2, also backward compatible with HomePlug AV standard, which means TP-LINK AV200, AV500, AV600, AV1200 are all compatible with each other. But it then goes on to state... However, the Powerline rate will drop to lowest ones rate when use different AV adapters together What I can't figure out is, does it drop for per-device communication, or does having one lower one on the whole network cause the whole network to drop? E.g. I was thinking of buying a 2 pack AV600 starter kit to replace my broken one (connected to main PC in rear room) and replacing the one connected to the router. So would the PC then talk to the router at AV600 speeds, or will the fact the upstairs xbox/sky box etc still on AV200s cause the whole lot to drop to AV200?