We used KidsNiteOut.com on our Jan trip for the two older children, 3 & 6 and took the baby with us. We don't EVER leave our children, even with relatives, so I was very nervous with leaving them with strangers. The Kids Nite Out people were very professional, pleasant and experienced. You choose the demographic you want to care/not care for your child. For example, they asked if I prefered a "grandmotherly" caregiver, a male caregiver, a college age caregiver, or a "motherly" caregiver, or if I was uncomfortable with any of those. I chose college age and she did really well.
It is worth checking into. At least go to their website. What convinced me was seeing that they actually provide services to conventions and trade shows, so if an attendee bought children, Kids Nite out would watch the children while the parent attended the conference/convention/show. Plus, they go through Disney training and are sanctioned by Disney.
HTH!