Review on StarTech.com USB 2.0 AC600 Mini Dual Band Wireless-AC Network Adapter - High-Performance 802.11ac WiFi 2.4GHz / 5GHz USB Wireless Adapter (USB433WACDB), Black by Brian Avila

This seems to work fine on my Mac, a mid 2011 iMac with Sierra 10.12.5. The software is easy to download and install. Device plugged in and both it and the Apple Airport Wi-Fi were recognized immediately. Connected to WiFi with no problems. I'm using Little Snitch's firewall/monitor and they seem to coexist just fine. My Mac's internal Wi-Fi card has been suspect for several years. After a few hours or minutes it claimed to be fully connected but there was no access to the network. I had to turn Wi-Fi off/on to recover. No software or firmware fixes that I could find will fix the problem and there have been no problems with other devices. So far, this device has remained connected. It supports the newer "ac" standard (Mac was b/g/n), could possibly be faster, but I'm on satellite which is the limiting factor. I immediately noticed web pages loading faster and with unexpected surprise. The measured download speed has not changed. Maybe my internal wireless card was worse than I thought. Some caveats: - Signal reception is good, but not as good as the original. This is to be expected considering the small size of the device. If you need range, consider using an external antenna. (This one doesn't, unlike a post I saw for it.) - The negotiated data rate is about half what a nearby iPad shows, and slightly less than an iPhone in the same location. I assume this partly depends on the size of the antenna and the resulting signal quality. This uses native Wi-Fi control, not MacOSX control. This is a minor simplification, so you might be missing a feature. As with all third-party devices and software, there are always potential issues with ongoing support and timeliness of updates.