The newest firmware fixed one very noticeable bug for me. With the old firmware, using a ramp level up command, if I held the button too long, some bulbs would invariably reset themselves and flash rgb. I will also say that the zigbee controller on the Sylvania branded lights is different than the one used on the Osram/Lightify branded bulbs (that includes Gardenspots and Flex XL strips).
Thatβs madness. X8=$240 and I only paid $172 for them and they have been absolutely flawless, but they are on there own HE hub (with 5 or so GE in wall zigbee dimmers and around 60 other zigbee lights).