They are the bane of my existence. As hard as it is to get funding for new equipment into the lab, it is even harder to get funding to maintain what I've already got. At least there are some mechanisms for bringing in new equipment.
At current funding levels, the vast majority of my grants are spent on paying personnel costs. What doesn't go to pay the people in my lab barely covers the materials and supplies they use. A $5000 repair bill means a choice between starving my lab of consumables, or living without an important piece of equipment. It keeps me up at night.