I find Zomig works very well for me, but the key is to catch the CH early... It's tricky when in a cycle becuase there's often the 'pain scar' lingering so recognising when one is about to hit is important. If I catch it early the CH will only last about 10 minutes and I'm not too tired, but if I wait too long before the nasal spray then it feels like it misses the boat a bit and the pain lasts for up to an hour, then I get more tired afterwards probably from the pain - still better than 2 or 3 hours without it)
the other great thing about the zomig is it travels in my pocket
the last few clusters I've been having a longer 'warm up period' where the pain is lighter and the oxygen works to knock it out, and then the CH hit harder... in this stage the oxygen just seems to delay the CH for an hour / hour and a half, so when I get them at night I get little sleep... but the zomig knocks it out.
maybe it's the combination with the other meds that hits you harder?
I'm able to work on the zomig if I catch it early. concentration is tricky though...