Which Professional Book Editing Services Are Worth It?

I’m preparing to publish my first book and I’m considering hiring professional book editing services, but I’m not sure which ones are reliable. Are some better for fiction versus non-fiction? How can I tell if a service provides thorough editing without overcharging? I’m also curious about turnaround times, communication, and quality of feedback. Has anyone had personal experience with professional book editing services they would recommend—or warn against? Any insights would be greatly appreciated.