I have never taken restoril so I can't compare.
I take 10 Mgs of ambien every night. What I have found is that it doesn't make me drowsy but within 20 minutes I'm out. I have to take it right before bed otherwise I'll stay awake through it's effects. I don't know if that makes sense? It's weird.
I think it's a good sleep aid for falling asleep. If I happen to wake up I'm screwed.