I have 4 of them paired directly to smartthings and have had very little trouble. they do require custom code, which means they won’t work if the cloud connection is unavailable, and there is slight delay from the cloud, so just something to be aware of. (in contrast, if the dimmer and bulbs are paired with the hue bridge, execution is fast and local to the Hue system, but there isn’t a good way to see the dimmer activity in smartthings).
Since you mention covering existing light switches, I also have several of the Sylvania Lightify 73743 switches, which work well (though only have 2 buttons), and the official DTH for these (zigbee button) runs locally.