<< Its better to leave it on than remove for inspection. Remember, once removed, it must be cleaned and reapplied for optimal performance. >>
I haven?t checked the ASII I applied on my CPU about 6 months ago. I don?t want to risk chipping the core just so I can check on the condition of the thermal paste. If the temps ever go drastically higher, I?ll consider removing the HSF then, but I certainly wouldn't recommend removing the heatsink and fan every three months.