Have used conbeeII, zigahzig 2652, sonoff dongle-E (efr32mg21) and now a few weeks a SLZB-06 and all dongles before the last one had problems with my 20 devices iam running in Z2M. the SLZB-06 you can used it were you want! how you want! and its powerfull.....i live in a new builded house 2 years now, before with my conbeeII in an house from the 1960's i had never a problem. sinds i moved to the new house all the dongles ill tryed had a very long delay and were after a few days unavailebel. and now with the SLZB-06 it works under Z2M very fine, yes iam very content with this Dongle. (https://github.com/Koenkk/zigbee2mqtt/discussions/14861#discussioncomment-4328364) Thats my small expierince