Agreed. There's been a few of these threads lately and people spouting unmitigated nonsense about the dangers of sleep.
I love to sleep, so does my mac. I put it to bed at night with my remote and wake it up in the morning with the same. At the end of the day, OS/X is built on Unix BSD/Nextstep, it's essentially server-technology that is designed to be always-on. Hence running cron scripts and such in the early hours to help maintain the OS/hardware. These scripts don't actually run when sleeping, same as they don't when powered down so you should initiate them yourself to keep things tidy, either from the command line or with a GUI like cocktail or cache cleaner but to (pardon the pun) put this to bed once and for all...
Sleep otherwise has no detrimental effect on your hardware, OS or battery health whatsoever. Plus, it means I can fire up Front Row from my bed and dance my self awake!