Well, today Top Gear returned to the airwaves after a 6 month break causing the site to get 207,640 pageviews (that’s not users, that’s just pages loaded). The server didn’t even blink. Okay, so it was helped along by Squid, but it still did a magnificent job.
If you get TONS of traffic or are on an underpowered server, I highly recommend using it. 🙂