Shutdown/Sleep/Hibernate on Laptops

I'm aware of what each of these states does and how they relate to subsequent start-up times, power consumption, battery preservation etc. Sleep seems a little pointless as do most compromises, but are there any general guidleline on when it's best to shutdown and when best to hibernate the beasties?

My hibernate resumes are blisterinly fast and I'm tempted to leave my laptops in that state unless I'm not planning on using for a longer than 24 hour period (rare).

There seems to be an issue with disk wear & tear and it being better to hiberate your machines than shut them down, but it would be good to get a real techie's advice, if any advice is appropriate for such a general query of course.