Hard reload takes marginally longer, but has no potential to fail - its peace of mind. I have had cases when small changes to dev tooling or maybe something in state management causes a failure during HMR reload. And if you dont realise this quickly enough, you might waste a lot more time than HMR saves you. As I said its still quite useful for working just on UI, so its not all bad, but ideally I prefer to work on UI components separately to the app anyway, eg using something like Storybook.