Connection performance is usually ~1s for the adapters listed as high performance with a USB extension cable and good RSSI:
- ASUS USB-BT400 (BCM20702A0)
- Cable Matters 604002-BLK (BCM20702A0)
- Enbiawit BT403 (CSR8510A10)
- Feasycom FSC-BP119 (CSR8510A10)
- GMYLE 3340 (BCM20702A0)
- HIDEEZ BT0015-01 (CSR8510A10)
- IOGEAR GBU521W6 (BCM20702A0)
- Kinivo BTD-400 (BCM20702A0)
- Nuu You BT40 (CSR8510A10)
- Panda Wireless PBU40 (CSR8510A10)
- Pluggable USB-BT4LE (BCM20702A0)
- QGOO BT-06A (CSR8510A10)
- Raspberry Pi 3B+ (CYW43455)
- Raspberry Pi 4B (CYW43455)
- SABRENT BT-UB40 (CSR8510A10)
- SoundBot SB342 (BCM20702A0)
- StarTech USBBT1EDR4 (CSR8510A10)
- StarTech USBBT2EDR4 (BCM20702A0)
- Techkey PBT06H (CSR8510A10)
- TRENDnet TBW-107UB (CSR8510A10)
- UGREEN CM109 (CSR8510A10)
- Warmstor WBT-AD01 (CSR8510A10)
Experiences are expected to vary widely based on:
- the bluetooth adapter
- linux kernel version (run HAOS for the best experience)
- bluez version (run HAOS for the best experience)
- interference and number of bluetooth devices in range (less is better, see below)
- dbus implementation. Use dbus-broker for best results.
- cpu time availability. Check your system with the profiler.start service
- bluetooth adapter firmware
See BLUETOOTH INTERFERENCE WITH OTHER DEVICES
I also get 1-2s to connect and execute commands for me using a not recommended ZEXMTE BT-505 adapter with -63 RSSI and a USB extension cable, however some users reported much worse results with the RTL8761BU if the system cpu performance is not so great.