That's a strange one BlueEagle, one would expect temazepam to have fewer residual effects than Zopiclone. These are based upon studies of civilians and driving ability of course, not military pilots in combat. Even so, Zopliclone is the worst of the three 'z's for residual effects on driving, the other two are not bad at all if used sensibly.
even Zopiclon may have been superseded by now!
Zopiclone was never licenced in the US, but a derivative (eszopiclone) was recently licenced for insomnia. This is supposed to be so good that you can use it long term - of course they said that about the benzos.
Would agree with gingernut that I'd rather a jetlagged pilot get some sleep before heading back across the time zones. If (s)he cannot do so normally then sensible use of a 'z' drug would be OK by me as a pax. Zolpidem is allowable in the US for pilots, but not within 24 hours of flight, and not for circadian rhythm disturbance.
I use zolpidem occasionally when in economy for long haul, it's very useful. It doesn't help with jet lag, mainly removes me from the boredom and gives me some sleep where I may get none, but I'm very happy to drive a rental car when I get to the destination having taken zolpidem some 10 hours before. The best prevention for jet lag (for me) is plenty of water and minimal alcohol.