Apple is nailing down the iOS 27 look with Beta 5, and the icon changes show they are still willing to iterate on the core visual system right up to the release window. I have been through each of these developer betas, so I could truly understand the pain of the development release cycle and get a hint at what is to come.
On macOS, Dev Beta 4 was a bit of a mess, to be honest. There were memory leaks, and I also heard about (but luckily didn’t experience) data corruption on some attached hard drives. I did have issues with the menu bar simply consuming memory and becoming locked or unstable, and I had to run a terminal command hourly to kill and restart it (which got me through the weeks between macOS beta 4 and beta 5).
While I’m only about 12 hours into beta 5 for macOS, iPadOS, Watch OS, and iOS, they all seem much more stable and performant. iOS 27 Beta 5 has been smooth thus far. And iOS Beta 4 was actually quite good (not like its sibling on the Mac). The refinements continue to come!