I was having zigbee device dropping issues and I’ve been looking at the zbt-2. I was hesitating due to the price. I went to take another search this evening and there’s one listed at a huge discount. I’m not going to post the link here as I’m unsure of the rules, but it’s easy to find on Amazon.ca.
Can you give more specifics about device drops? Have you looked at the mesh layout in HA to see what connections are being made between devices?
You may not have a distance issue that a new adapter will fix. You might just need a repeater/router.
My first ‘issue’ is I have everything in ZHA. I want to move to Zigbee2MQTT, but with 40 zigbee devices and associated automations it’s a pita. So I figured get the zbt-2 and migrate that way. ZHA doesn’t report LQI and RSSI, so measuring the mesh isn’t completely empirical. First issue was a window sensor I use for the mailbox. It was a 3rd reality sensor and it was losing network connectivity about once a week. It’s just outside the front door, and I have a 3rd reality zigbee outlet in the front entrance. The Sonoff coordinator is mounted on the wall at the bottom of the stairs, which go down from the front entrance. (difficult to visualize, I know).
I then tried another window sensor on a closet door in the kitchen to trigger a light when the door was opened. Another zigbee outlet very close to the closet. Sensor (aqara in this case) can’t stay connected for 5 minutes.
So, considering I want to migrate to zigbee2mqtt anyway, I figured this was an opportunity to experience that pain.