I gave Safari 4 a whirl on both Mac and PC. I like it. It brings much of the cool stuff from iTunes into the browser. Cover flow is fun and fresh in a browser. The Top Sites with the page previews is an upscale rip off of Chrome and, really, it’s a good feature for any browser.
Safari 4 is great for casual browsing and general perusing of the code but web development work stills needs the robustness of the Firefox plugins. Firefox is so ahead of the curve for web developers and I’m so used to it’s fantastic toolbars and debuggers that I don’t know if anyone will catch up. Granted the Safari 4 Web Inspector on the pre-packed Developer toolbar is nifty. Gotta love the ‘Resources’ tab. Nice visual of the weight of each loaded item. The included scripts debugger is handy and a much needed accessory in every browser.
Did I mention Safari 4 is fast? It is. That my biggest complaint with Firefox. It can be slow to render. Maybe that will improve with FF 3.5. Still, the trade off at this point is worth it. Bottom line is Safari 4 is great for browsing and the Web Inspector is a must ‘once over’ tool for developers.
FYI, Lifehacker has a great article on the latest browser speed tests.