Same boat. I'm still on Sierra and still have concerns as a colleague on High Sierra almost hosed his system with APFS. Any stability issues on the new file system?
HFS+ was terrible, but at least I knew most of the ways in which it was terrible.
I've always found Spotlight to be utter garbage, but that's not the fault of HFS+.
The system requirements for HFS and HFS+ reflected this and partially explain why there was little progress for literally years at a time.
https://arstechnica.com/gadgets/2011/07/mac-os-x-10-7/12/#hf...
Eventually, you have to start over.