It's all relative.

If you'd asked me what a good night's sleep was 6 months ago, I'd have said 8-9 hours of uninterrupted slumber.  We'd been spoiled by Maeve who was an easy baby (comparatively) and was rarely up more than once or twice a night before she started "sleeping through the night" at 14 months from 7 pm-7am.
Things are a little different these days. ;)

I'm giddy over last night's sleep.  The twins went to bed at 7, and only woke at 10, 1, and 4 to eat (at the same time)!  Trust me, that's a monumental improvement given what the norm has been for a solid couple of months. I'll ignore the fact that Beckett likes to wake at 5 am for the day.  I don't feel bleary eyed this morning and can actually think clearly, which is a good thing as I get ready to go back to work on the 13th of September.  Eek.

Like I said, it's all relative.