Anecdotal, but at least M preview 3 on my Nexus 6 is much worse. Hangs for a second some places, etc.. I'm a developer so I had to install it to test the new permission system in my apps, but I wouldn't recommend it to anyone. They also broke most of the mock location provider apps out there by changing that developer setting for no reason.

The number of settings in general seems much less (I'd kill for a setting to disable that immersion mode that hides my back/home button, personally, but no luck) so I think they are going full steam toward Apple style, they know what is best for you.