So far I have not had any of these summon, and all can be snared. Occasionally one is a bit resistant to Darkness, but overall they aren't too hard to split and kite along the beach on Suncrest Ridge. Some of these drakes are casters. I killed one tonight that cast wizard spells and summoned a wizard's sword pet to fight for it.
The experience isn't bad for my 67 necro, but mostly I am killing these for the Steamdrake Potions task as one of the 39 tasks needed for the Jonas Dagmire's Skeletal Hand quest.