The most striking UI change is the re-worked tabs. Other authors have posted in defense of the new tabs, and I understand that the main argument is that the tabs in Safari 4 Beta better represent the document hierarchy. The tabs-in-title-bar supposedly represent something more like docked sibling windows. For example, Manton Reece writes:
The Safari 4 tabs are conceptually the right way to go. It's not "tabs" at all. Instead, think of it as an efficient way to dock multiple windows together.
I'm not sure if I'm buying the premise that there needs to be a one-to-one correspondence between web pages and entire windows. The old tabs caused me no confusion. I agree with Reece that if this represents Apple bringing system-provided tabs to applications, then that's great. I just wouldn't do it like this. Let me add my own list to the numerous gripes detailed elsewhere:
- Tabs in the title bar give a window a very cluttered look.
- The first question I had was "Well, where do you grab to move the window?" It turns out that if you grab the tab-dragging affordance on the right, it moves the tab, not the window. If you grab the tab close button, nothing happens on drag. You have to pick a spot between these two icons on each tab.
- The tab with focus is wider than the tabs without—which is fine, but the unfocused tabs are now so narrow that often there's no space for any useful excerpt of the page title: about six characters and ellipsis.
- The tabs move when cycled. In Safari 3, the leftmost tab was fixed, and cycling right eventually moved into the non-visible tabs. In Safari 4 Beta, the whole row of tabs shuffles left or right to move the focused tab into visibility. I can't decide whether this is better or worse, but coming from the old behaviour, it's at least disorienting.
Beyond tabs, I have two small UI criticisms. The loss of the progress-meter-in-address-textfield (the blue background that moved across the address textfield as the page loaded) is remarkably annoying. Evidently I used it subconsciously way more than I ever realised, as now I find its absence incredibly frustrating. Moving the reload button from the far left (and outside) of the address textfield to the far right (an inside) seems arbitrary and, again, is incredibly annoying.
On the upside: it feels fast. Ars Technica has taken a brief look at it, and, while noting that it might not be as fast as Apple claims, that it does, indeed, seem faster, and features better resource management.