I agree 100% with the complaints here. Why aren't they fixing it???? Responsiveness + consistency is EVERYTHING, and Fluid is not there yet.
I have spent too much time trying to make Fluid work properly: tutorials, code, research, and testing. I've given up. Live chat support has always been great but has been useless for this. One thing I do suggest is that you try to use both classic and fluid sections mixed on the same site. Fluid seems okay for specific sections, so I have been alternating and testing it. Good luck all.