I recently saw it referred to as the "shake a lemon at God" holiday. Around my house we call it "Huddle in the Hut."
In ancient times this was the biggest celebration of the year, with a carnival-like party atmosphere outside the Temple in Jerusalem. It's one of our three oldest holidays, and I enjoy it for its historicity as much as anything else.
My own personal philosophy is, "We had to camp in the desert for 40 years; we don't have to do that anymore."
But honestly, I don't think anyone around here actually sleeps in their sukkah. When I was a kid we did it a couple of times when the holiday was "early" and the weather still warm-ish, just as an adventure. If I lived in the Middle East, I might be tempted (weather in Tel Aviv this past week: highs in the mid 80s, lows in the low 70s) .
ETA:
I just took the dog out for a walk and, despite the drizzle, it seems the new family that moved in down on the corner last month is having one heck of a Sukkot party. It sounds like there's about 20 people in their sukkah and they are singing and banging on tables VERY loudly.