I've got a pair of these running in my house, as a temporary solution to get wired Ethernet to an above-garage loft with no CAT cable, just one RG6 for satellite TV, no easy way to quickly run a new cable, and poor WiFi coverage despite the AP being right at the bottom of the stairs.

Despite being a much shorter run than 300', speed is nowhere near 1000mbit. Maybe 100-200mbit max. Latency is also quite high (like WiFi levels). BUT - it actually works, it works very reliably, and there's zero glitching when streaming high-bitrate (50mbit) video.